I'm on the same page as the others, in terms of looking at what exactly it is about being female that makes you uncomfortable. Because some people are uncomfortable being female, but that doesn't necessarily mean they want to be male. I've spoken with women who questioned if they were transgender when they heard about the whole "not feeling right in your body" aspect - and after contemplation, they found they had different issues entirely. I'm not saying this is you, just giving you some stuff to think about based on my experiences. The women I met...they didn't want to be male, they just disliked certain aspects of being female because of society. I knew two for who it was an eating disorder. They saw men as thinner, less curvy, and wanted that same lanky frame without all the other aspects of being male. Others had been abused (sexually, or emotionally) and believed that being male would make them "safer." They didn't want to be male because they felt they were male, they just had serious struggles around certain aspects of their femaleness. And that's worth investigating, because those problems won't go away with transitioning. Even if the outside is male and people treat you as male, your original issues still remain. Plus, the possibility of being unhappy with your new sexual characteristics - body hair, male shape, etc.
I can tell you a little bit about my process, because it was long for me and I overthought a lot of it so I know the little nuances, lol...I first learned about FTMs in late 2006. I knew that many things they spoke of resonated with me, and I felt like "this is what I am going through", but I knew it wasn't going to be easy. It's not often as bad or as tragic as cis people make it out to be, but it can still be very hard and isolating. So I looked into seeing if there was a way that I was a cisgender woman. I started experimenting with wearing men's clothes, and worked on my confidence and personality. I knew that I wasn't expressing myself fully - I come from a family that's quite sexist, so I grew up feeling restricted in a lot of ways. I wanted to overcome those before I looked into transitioning, in case that's where my discomfort was coming from. And yeah. I felt better in men's clothes, and with short hair. I cut bad people out of my life and surrounded myself with people who shared my values, believed in me, and helped me to empower myself and be a confident, functional individual. I found a really great girlfriend who loved me no matter if I was male or female. That transformation happened over about 3 years and I really was like a completely different person. I don't like to gender it, because it wasn't about gender - but objectively, I went from living a stereotypical "female" role to living as I wanted, knowing I had the option to do anything that a man could do. That's key. Knowing that regardless of whether you are male or female, you can do whatever you want to do and be happy and successful. I hear about too many people saying they can't partake in "X" activity until they present as male, and that's a bunch of crap. You can do whatever you want, whenever you want. Sure, I got some dirty looks, I got some people making disparaging comments - but people will do that no matter who you are, or what gender you are. People are just mean. At least I knew I was doing the things I liked and I had people who genuinely loved me for me.
But anyway, over those three years (since you asked how to accept it if you realize you are in fact FTM)...in that time I kept reflecting on it, because although so much had changed - my appearance, my role, my confidence - I still felt discomfort around my female body. I talked to my girlfriend about it extensively, telling her my fears about being trans - the hassle, the discrimination, the possibility of looking "weird", not being able to afford it, being disowned...but the biggest fear I had was that I wouldn't be normal. I told her so many times, I'd rather be a gender non-conforming, out lesbian, cisgender woman than have to deal with my trans feelings. I'd rather deal with ignorance than deal with confronting my body dysphoria and making myself so emotionally vulnerable by telling everyone that I was really a man when I looked so female. By that point we both knew that I was trans and that this was a real thing. She always said to me "maybe you wouldn't be seen as normal to the outside world if you transitioned, but what is normal for YOU? You have to realize that you'd always feel abnormal inside - all the outside acceptance won't even matter if inside you are suffering."
So I accepted it...by, well, realizing that it was a thing and that it wasn't going to go away. I saw that I had done everything to try and live as a woman. I fully accepted my love of women, and held my girlfriend's hand in public with pride, so I knew it wasn't internalized homophobia. I'd fully integrated myself into a number of women's studies classes, and suffered a great deal of anger over how our society treats women - so it wasn't internalized sexism or misogyny. I'd overcome all my fears and done all the things I used to tell myself a woman couldn't do, so I was expressing myself fully and didn't want to transition to fill a male role (as I could do that in a female body, easily). Some people thought I was weird, and I truly didn't care...I just laughed at them for limiting their view of what each gender could do. I didn't see any other way to explain why I had the feeling of wanting to have a male body since childhood. So that was what drove me to accept it - I just saw that it was the way it was. That it wasn't going to go away. So I could either do something about it, or as my gf said, always have these bad feelings inside and suffer.
Now do you have to take 3 years like I did to rule everything out? Probably not. Really, what it came down to in the end was that I was scared. I wanted any other explanation so I didn't have to transition. But I am glad I considered all the things I did, and I am glad I worked on myself as a person, because it has given me more strength and conviction to deal with the challenges that come with being trans. Not going to lie, I still wish I was cisgender. Cisgender man, cisgender woman, I don't care - I just hate sometimes how long this process is, how hard it is to access the things I need (surgeries in particular), people's ignorance towards trans people (some people can tell even farther into transition, either because they were told, or because they see a lot of trans people and know the physical features). It's tough. And if someone could find a way to live without transitioning, power to them, but I have accepted that this is my hand in life.
