I'm sorry to hear this, hon. Without presuming to know what you've dealt with beyond what I've seen from your other posts, you and I are similar in age, and I've had those crying nights, too. I've even had moments of suicidal ideation when the depression went too deep. I've felt like the girl inside me is in a cage, and when I want to present as female but can't, I imagine I'm being forced to push her back down into a terrible cramped space. It sucks.
But the other side of this is that we're still actually pretty young. I tend to feel like I'm old when I stand in front my teenage students or by my younger cousins, yet the reality is that we are still not old. Many people, moreover, transition decades beyond where we are now--and they look great, and are happier. And regardless of age, when we begin presenting as female, it's like a kind of rebirth. Obviously, we aren't literally regaining lost youth, but we are gaining a chance to live life from here on as we always wanted to--and we get to begin to experience the things we hadn't. The first time I went out in a dress and leggings, I walked in front a man by mistake, and he stopped, stepped back, smiled, and bowed to let me pass. It was silly chivalry, and yet it meant the world to me; I was always the guy doing that myself, and suddenly, I had become the girl on the other end. And when I went shopping with a friend to Sephora once, and we got called "ladies"--well, even if they were just being nice and had read me, they had read me correctly as a lady in the right sense, and it meant so much to me.
Being trans* means struggling for almost all of us--but the rewards will be worth it, I hope, even as the struggle will continue. I am struggling so much with coming out and with family issues all set alongside heavy schoolwork, yet I take joy from the little moments where I see the girl in me--and others do, as well, because she is no longer the girl in me but the girl-who-is-me.
I'm there if you ever need to rant or anything, and there are many other people in this age range on here, too. If you stay strong, I hope you'll get through. Take the small moments--and go from there.