At some point you have to choose, or it'll be chosen for you.
I am 24 years old, though I feel as if my life is much held back compared to where it should be at my age (thanks to being trans.) I'm pursuing transition and am on the verge of legal name change and complete full time - I still work 'male.'
I will share a condensed block of my life, take it for what you will.
I was always ma'amed, throughout my entire life. Even with a ZZ Top beard. People heard my soft voice, saw long hair, saw that I was very short, and ma'amed me. Especially after I shaved it (which didn't happen til I was 18.) It used to piss my mother off. She would scream at waiters/etc. At first, I corrected people. I stopped, eventually, just because it got tiresome.
A few months before turning 19, I truly realized I was trans and my world imploded. Several dark years passed, culminating in living across the country for a while.
After I returned home, I did the no body hair, womens' pants/jeans/t shirt/button down/shoes thing. Got my ears pierced. People who knew me as a guy said I looked like a rockstar. People who didn't know me as a guy increasingly called me ma'am. I grew so uncomfortable doing everything. I never knew when someone thought I was a woman or a man. I originally assumed that everyone knew I was a guy... then I got kicked out of a mens' dressing room. As things progressed, after receiving the confirming 'she', 'her', 'ma'am', etc, I would seize up, so afraid that I'd do something to out myself.
My voice always passed on the phone, and with very little effort became basically perfectly passable in real life. I do not mean that it is a gorgeous, Disney Princess melody, but that I have been called 'sir' on the phone a literal handful of times in the past year. Even while discussing banking/credit/medical information regarding my own accounts. To the point of having to tell one of my nurses that I do not menstruate because I do not have ovaries, not because i had a hysterectomy, but because I was born without them, because I was born a boy. That was a year and a half ago and she was reading my chart! I've had doctors walk in, address me as a woman, talk to me a while, thumb my chart, and their eyes bug out and get very uncomfortable. I had one endo think I was FTM before I corrected her. My GP PA thanked me with overwhelming happiness when I told her I was trans because she had been so confused when she met me, and assumed, but didn't want to say anything. She's a doll.
The thing is that all of these experiences continued to build me up. There is no better feeling in the world than the constant external validation of others.
Last week my Visa assets were frozen because my voice was female and my account was male. Funny, 3 years ago Visa employees still called me 'ma'am' when I called in, before estrogen or any voice training... but, if I had called in last month, my card would have been frozen right when tuition and books were due. I would have been screwed to the wall. And right now, I have no idea how I'm going to prove my identity to these people. It stops being cute.
My whole life, men have done double takes at me and been freaked out in the mens' room. Woman, fag, who cares, it's really uncomfortable. Until I stopped using the mens' room, from age 20-24, men would walk in, see me at the urinal, and leave the room dumbfounded.
I don't know what kind of job you work, but it's great to be sitting there talking to a customer, and they're chirping along, 'she, she, she, her, her,' and a coworker walks up and is like 'Hey dude sorry to interrupt man but can blah blah, thanks sir.' And then the customers stare at you like you raped their cat. Well, actually, most of them just completely ignore it and don't hear it or react to it. But I always fear what may happen. But I also had to stop mentioning "my girlfriend" in a relationship sense - because people thought I was a lesbian, and that did probably bother some people.
The other thing is name. I can't tell people "My name is _______" anymore. Where I *HAVE* gotten bewildered and uncomfortable reactions from customers, the only ones I've personally seen (not to say it hasn't happened behind my back), was when I told them that yes, my real name is my male name. I have to tell them "I go by ____" with a smile and not linger on it, not act like it's anything special. Just a grown up tomboy who provides great customer service.
If you don't work with clients directly, it'll be different of course. But still, even in every day conversation... until I began just simply asserting myself as female, it was hard to hold conversation. Think about holding a gender neutral conversation. Don't mention your partners, past relationships, any experiences growing up that you had because you're a boy (or a girl), etc. Talk to people that way. Consider how bizarre it is, and that's what I lived with when I was in the grey place, never sure if I passed or not.
Interjection: because I work in sales, relating to people is my lifeblood. It's all about breaking female things down into bites for men to digest, convincing women that male things are not impossible for them, to show that I can relate to either gender's needs when it comes to comprehension and conversation.
But you may not meet dress code. Hair is a big one. Otherwise, you can go very metro (isn't metro retro now? ha ha) with skinny blouses and pants and fitted suits and all, but let's be honest, me wearing a darted waist blazer and fitted slacks does NOT look like a man's suit and is going to at least raise queer flags in a lot of places.
May I also interject that it is very frustrating to trade one box for another? To go from being seen as a guy, to being seen as a gay guy? People talk behind your back, people assume things. Some people like to rub in that you're a guy, "You're a guy, you should do that instead."
Worst is when guys eventually start hitting on you... and you have no idea if they're gay or straight. At least in the south, gay guys don't usually openly flirt, so, he's probably straight. And then you start worrying about getting the >-bleeped-< kicked out of you.
Here's another part. Estrogen changes you. There is no way to look as feminine as possible and not be seen as a woman... except, the dreaded alternative, the "man in a dress" caricature. You're gonna grow boobs if you go on hormones. People will see at some point, depending on what you do to hide them. When I started estrogen, I didn't think my breasts were obvious at all... until I heard classmates discussing them. You won't be able to go swimming, or take your shirt off. Skinny boys don't get breasts normally. And if you roll with it, tell people it's an endocrin system thing, they'll call them moobs. Do you know how depressing it is to have your breasts called moobs? Also, eventually, running with breasts is very hard. I stopped running most of the time, and I used to sprint everywhere. And now that I'm tucking, I walk completely differently than I used to. I have to. It's feminine body language.
The other part is, if you don't take hormones, you will continue to masculinize. Everybody is different, but the best results occur before the mid 20s, certainly before 30. The male face continues to change, and late 20s is honestly the male prime.
So you either go for hormones, and get to the point that I am living at, where trying to convince people that I was a guy at any point is pretty futile, your safety becomes a MAJOR, MAJOR concern, socially, everything is awkward as hell, and wearing mens' clothing just makes you look like a lesbian (which might get you gay bashed. Goddamn, it's ridiculous being ridiculed for being a dyke AND a fag) or, you do nothing and watch your feminine qualities fade with age.
I chose to go with the hormones and transition. I can't imagine living life as a man at this point. Going to work 3-4 days/week as a "guy" is a punch in the head to me. Customers always call me her, new employees call me her until they catch on, and I get "thank you sir" for being a performance leader.
Also if you pursue hormones your sexual function will change. You stop ejaculating, sex drive drops (usually), and if you do not actively maintain your equipment, it goes away. I was asexual for a few months and lost some size and shape. I'm exercising it these days and it seems to be less painful and to have recovered some, but I've got some permanent loss probably. My ex told me she missed the curve I used to have. You can maintain a healthy sex life, but it will still be very different.
Personally, it started out cute. All the minor victories, the self-esteem boosts from passing... then the times I didn't pass were a punch in the gut, even if I didn't lose anything (androgynous clothing.) Then it starts getting serious when you have problems proving your identity, or the people in your social area start noticing things...
My mother always told me to live life in the middle. "Be a woman, keep your dick." "Be a woman on the weekends." "It doesn't matter what other people think."
Yeah, mom, because, clearly, none of the above issues are a concern. Clearly cutting all my hair off to get a better job isn't going to depress the >-bleeped-< out of me. Clearly getting hit on by a straight guy and getting beat up isn't a possibility.
Standard disclaimer is that my life and body is wholly separate from yours, my opinions are not 100% fact, and your results may vary completely from mine. In the above, 'you' is used in the universal sense. But anybody who thinks they can just continue to live as a guy going through this is wrong. And once you have the balls off, you have to be on a hormone treatment of some type... E or T.
And do NOT go on spiro by itself to 'middle of the road' it, you will likely suffer rampant bone density loss and fatigue.
I also cannot stress enough how challenging it would likely be to continue career improvement/job hunt, depending on your field/area, as someone who is flamingly genderqueer. The whole 'get hired, then, let your hair grow back out and dress how you want" caveat applies, but, when you walk into HR for an interview, they expect Mike, they see a plain looking woman with small breasts, who says "Yeah I'm Mike" and her papers all say Male...