To answer both of your questions, Cindy...
For your first question, I never exactly tried to fit in with girls to be "normal". I knew that I wasn't "normal" like most other girls I knew (feminine, heterosexual girls) and the only girls that I really felt a kinship to were tomboys when I was younger because we played similarly. But I was raised to think that prettier was better and so the prettier and more attractive I was the better I thought I was in comparison to other "girls".
For your second question... consequences that came from this...
I had a huge problem with body image when I was younger. I always thought I should be skinnier and have less hips/butt (read: androgynous, though i didn't know the term/concept at the time) and I hated any curves that appeared on me. So when I was younger I had a huge thing to become as thin as possible. I neglected my food intake and counted calories so I could stay as small as possible. When I became a teenager I went through a body positivity phase, where I tried to embrace the body I had and I honestly think it made me even more distant from it. I kept telling myself that nothing was wrong with my body and other people were happy and gorgeous with bodies like mine. So I mimicked them and played dress up, essentially, starting to see my body as more of an object than anything else that I paraded around to get attention.
This led to severe bouts of depression and anxiety when I grew into an older teen. I felt a sense of loss within myself, as if I couldn't recognize who I was, but I still couldn't quite figure out why. But the more and more that I tried to push myself into femininity and showing off my feminine aspects, the more uncomfortable and despondent I felt. I also completely tried to shut out my feelings of wanting to be male/seen as male/be recognized as one of the guys again because I felt that was impossible and I'd never attain it.
Later on, after I realized I was trans, I still went back and forth trying to be a girl for the longest time because my family was a huge obstacle and I knew they'd never accept it. But it got even worse, so every time I tried to force myself to act like a "normal girl" (at this point in time I was actually trying to be normal and fit in), my mental health got even worse and I started having suicidal thoughts and self-harming. And at that point I just kind of gave up and realized there was no way around it.
Also, that warning about birth control that Cloudchamber posted is a good one to consider for FTMs. When I started dating my first boyfriend I went on birth control as a preventative and it made my dysphoria flare up really badly. My mood swings were out of control and I wanted to violently harm people. Also the whole bigger chest and body fat thing wasn't good for me either. And popping a pill a day reminded me that I had internal reproductive organs that I'd rather not have so it sent me into severe panic attacks until I could disassociate from it.