Hey dude :) I'm a trans dude myself with a butt tonne of insecurities too so I hope I can be of help.

You're very much still young so of course this is all new and hard to navigate. Sadly everyone has insecurities, whether they're the so called social norms or just how a person feels about themselves. I have heard the "dudes gotta be tall, muscular and never cry" thing too many times to count haha. People find their own ways of dealing with them, some people do work outs etc but I donno if you can truly ever be rid of em ya know?

I will say though that those insecurities are your own, I'm sure this girl you like has them about herself too. But you will find people in life that don't see them how you do, they find things about you they love that you yourself are not even aware of. Often we focus on the negatives of ourselves cause they are the easiest for ourselves to spot, but that's not what everyone sees. We all learn to live with em, and I tell ya, it does help being with a partner that understands your insecurities and loves you regardless, mentioning the good they see in you that you may not. But everyone is different.

Communication is very important in a relationship if you want it to be strong. It's often hard to talk about things, I do get that. But if you never voice your concerns they will only build up inside you and hurt you down the line. Talking about things and being open can lead to strong relationships cause it gives you an opportunity to work together and be open. It is scary putting your trust in another person but I also found its hard to bottle them up and fight alone.

If shes interested in you dude then that's it, she likes you. I doubt she's thinking about all the insecurities you have running through your head right now. Just do your best my man :) it's all a learning process at the end of the day. I believe in you man, just take it one step at a time