I feel so lost and useless, so empty.?

Hello, I'm a senior in high school, ready to graduate. I'm a boy by gender and 17 years old. Some say this is the most magical year ones life in school. Unfortunately, it has been personal hell. I feel surpressed trapped and caged, and i've always been a wild card, and this imprisonment i seem to be trapped in is killing me inside. there are so many problems that its impossible to sort through it all. First, the most traumatic and horrible thing that can happen to anyone, is i have gender identity disorder, which means i'm born in the wrong body. having to live as a boy but secretly inside i'm a girl. Wanting to do girl things, thats one of the major supressions i find tough to over come. the natural ability to fully embrace who i was born to be, yet can't become. second and i'm horribly insecure, i feel like i'm a freak. Everyone is normal despite there petty problems. i feel i cant over come my problens and i will be subjected to a life of regret and emptiness. It kills me to see all the girls around me go shopping for prom dresses and talk about their hair, and dates. and i know its shallow and stupid, but it hurts that i can never experience something as simple and as beautiful as the ability to grow up. I've fought hard to surpress it, but i honestly can't anymore. I'm so uncomfortable with everything i don't know how to go about my day. Another problem is my home life. Its rocky, and no one understands each other, i've longed for someone to talk to, tell them what i really am, but i dont want to be labeled as a freak, i'm already dealing enough with my own judgement and my own personal self loathing to hear what others think of me would push me over the brink. I'm so fragile, yet i feel like i have to live up to this facade of being so strong and manly. I havent seen my dad in 11 years and the only way i contact him is through phone, his support isnt here. and my mom would never understand me. I feel so useless, why should i exist if i'm not ment to be what i am. I feel if any sort of higher power exists i loath it for making deal through this. And at a time where we should be excited to explore life, i've never felt so vulnerable, completely warn out and depressed. I wont kill myself because my cousin commited suicide and i saw what effect that had on everyone, and however tough i have it i wont subject my family to that. And above it all i feel like i'm ugly, like no matter what i do, where ever i turn to find a resting spot for myself i can never be completely free. I don't know what to do, honestly. i need help, i've seen therapists but i cant get myself to open up. I'm lost, I'm caged i need to be set free.