My path to realisation was kinda weird and internal. I first realised I wanted to wear girls' clothes because they 'suited' my personality better around the age of 12, but I brushed it off because hey, that was 'weird'. The phase would pass, right?
13, and I was female to everyone online that wasn't a real-life friend. Had no idea about hormones and my legitimate interpretation of a transsexual was your typical, slapstick 'man in a dress' visual... which I didn't want to be. I was heavily questioning myself at this stage.
17, and I was still female to everyone online that hadn't heard my voice. I was more comfortable as 'her' than I was as the person everyone knew me as. When some people found out that I wasn't 'really' a girl, their reactions were negative. I started to think of myself as a freak and got depressed. Due to a chronic medical condition, I was already pretty down and this only made it worse.
18, I got my first girlfriend. She was the first person that made me feel comfortable when I looked like a boy. Though I was in love and it was a fantastic experience that I wouldn't take back, I *often* looked at her and thought 'I wish I could look like that'. She loved my sensitive side because she was from such a rough and 'tough' family and loved to cuddle all day. It eventually ended due to her needing to move for University; I didn't have the money to follow and she couldn't not take her opportunities as they came. Unfortunately this left me with a 'he' that I hated.
20, my chronic condition is keeping me in high school so that I can finish it at my own pace. I had overcompensated since my ex left me and grown a thick beard that I left there basically because I was convinced I could never be the girl that I knew inside. Then I came across some MtF resources - real ones. Ones that told me all about HRT, which up to this point still held that 'man in a dress' stigma for me and I wasn't convinced... until I saw a BUTTLOAD of before and after pictures from all kinds of people! People that were older, more typically 'masculine', and that had a worse family situation than me. And yet they decided to make what was wrong within themselves right!
I did a ton of reading. I watched documentaries. My heart ached because I knew. This was what I had been feeling.
And it kinda hit me like a sack of bricks. I took a real good look at myself in the mirror, picking out all those little things I hated. Then I looked for the bits about me that were feminine. I only found a few, but... to answer one of your questions, I wondered if it could get worse. I wondered if I would rather continue living as this person that I didn't relate to in the mirror, or potentially, as something between both genders that would never pass as what I wanted to be.
I decided I'd rather take a shot at happiness than settle for this body I'd been given. And that's kinda all that you need when it comes to this sort of thing. Coming out, whether it's to yourself or to your family, is so heavily influenced by what you believe and what you feel that you NEED. I
want to be pretty, but I
need to be female in order to be happy.
I know transition is the right thing for me, even though I'm still a couple of months from my HRT, because I feel so much more confident in who I'm going to be. I have goals, ambitions, and about a million progress selfies to look forward to. None of that existed before; my world was grey and full of distractions. Sometimes I wonder if I'll ever be able to get a convincing and natural female voice. Sometimes I wonder if I'll ever be able to slim down enough to look the way I want to look in a skirt and t-shirt. It could get worse - I don't know if it will or won't. But so far, rolling the dice has made me happier than I've been in years.
Not sure if this novella would have helped, but that's been my experience so far. You will face difficulties. You might not even know what you are for a while yet, but if you think this might be a problem that you're facing, and you relate to any of these feelings, then I'm sure almost everyone here would encourage you in exploring your identity as early as possible. After all, the sooner you start to transition, the better your results will be, and even if you don't transition, you might have worked out who you are along the way... and that's priceless.
Boy I sure can go on