I dunno if this will help at all, you're getting a lot of supportive advice from trans people so maybe a cis perspective could help?

I've never particularly wanted to be a girl, it seems harder. I'm happy and comfortable in my body, I like my dangley bits, I like not having to think too hard about clothes, I enjoy my privileged spot in society. Not being a women, I very rarely get randomly sexualized by others and when I do it's usually in an "I want him to do things to me" context, not an "I want to do things to her" context which is much less scary. I like the feeling of being in control and men tend to be given that as a default (shitty though that inequality is).

I love boobs to play with but they seem so impractical to actually have. I can easily imagine wanting to transition as a trans man if I wasn't born this way.

I don't look in the mirror and think "I'm a man", or that I'm sure about my gender or ambivalent about my gender or that I don't care about my gender, it's simply not something I even think about ever. I rarely consider my identity at all. Most introspection I have is about what I could do better, not who I could be. Being a man is a given.

Of course, I don't speak for all of the cis, YMMV. There's plenty of middle ground and genderfluidness and enbies etc., but thats my experience.