Stuck between depression and parents, going nowhere good

So. I have been struggling with how to deal with my parents for a long time now, and have got nowhere. Now I'm starting to lose it. I don't know what to do.
Here is what happened:
Back in elementary school, I was headstrong and impulsive. I felt different from everyone else, and desperately wanted to be accepted by them. I let what people said get to my head, and did stupid stuff. One time, jealous of what the other kids had, I ransacked my parents computer drawer and his thing in it behind the books in my room. Another, I snuck into the guest bedroom to watch Adult Swim. I've done other things too; some pretty bad stuff.
In about sixth grade, I began developing depression (not that I recognized it as such at the time). I became paranoid and secretive, and began to be a darker person.
In seventh grade, I began exploring sexuality. In the beginning, I went after girls... But I slowly realized there were other options. I was afraid of this, because I went to a homophobic school. We had one openly gay kid; and the guys avoided him like the plauge. But by eighth grade, I had subconsciously realized that maybe I wasn't exactly straight. I was still terrified of the thought, however.
At the same time, I was dealing with other problems. At home, my family was totally dysfunctional. I was having trouble with them.
At the end of eighth grade, I went to the woods with my best friend, and we had a game of Truth or Dare that ended with us having sex (almost - we didn't reach orgasm, or anything close). That did a whole lot of good for my head, as you can imagine. (Gay sex with my best friend? What was I doing? And even worse, I... Liked it! This was horrible! And so on. In an ironic twist of fate, I found out later that he was gay and liked me.)
When I moved to South Carolina, I put all that behind me. It was going to be perfect.
Fat chance.
I went to a bad school, but it was okay. But I still had huge family problems. However, I somehow managed to put up with it.
Then we moved.
My new school was wonderful. The only problem was me. This was when my depression got worse.
In the second semester of ninth grade, i for suspended and threatened with charges. For playing Minecraft and getting my saves off the hard drive with 7-Zip. After that, my parents never trusted me around computers again. This was a fucking pain, because I'm a nerd: computers are my life. But ever after, I was forced to be watched when I wanted to go on the computer at home. (Right now, in fact, I'm writing this from a phone they don't know I have, so I can talk openly.)
In tenth grade, nothing new. It got worse. Then (being in an open-minded school) I accepted myself as bisexual (wrongly though, because I'm pansexual). I began to figure out I was transgender.
Finally, in eleventh grade, I lost it. Grades fell down the toilet, I can't even converse with my family anymore, I feel like shit every fucking day, and my mind has completely stopped. (Before: Alienware. Now: Gateway (2K era).)
To top it all off, I'm in such great pain that I'm contemplating suicide to make it stop.
I don't know how to get out of this hole. Can somebody PLEASE help me?

(If you want more information, just ask. I can give it to you later, once I'm on a device with a real keyboard.)

 

Thanks...
Well, probably cliche but I don't want so much to die as to stop hurting. I don't know how to keep coping with my family, and not to mention if I don't get this fixed soon so I can get my grades fixed, I'm screwed because I'm relying on getting a scholarship to get a ride to college (I can't afford it on my own).
The thing is, I don't know how to keep dealing with this. I CANNOT keep on like this; I need to get this whole situation fixed and NOW. Before I completely lose it. I'm considering walking out, but I don't know where to go. I'm stuck.

 

Last night was crazy...
In the morning, my mom searched my backpack and found that I'd gone to RadioShack to buy a Bluetooth speaker, and bought $10 worth of Valentine's Day candy to share with my friends at school. She then cut up my debit card.
First off, I'm not even sure that that's legal because my name is on the account, and my dad's, but not hers. But more important, that card was the key to my freedom. That card meant I could support myself in the world without them. And she cut it up and threw it in the trash.
Then. I tell her, "that's so mature of you." She flips out and has this "How dare you inferior being subvert my infinite wisdom and godliness" attitude. I get on my shoes and get ready to go.
Well, after adding this shit on top of everything else, I freaked out and lost it.
When I left work that night, I tried to go to my friends place. But he accidently gave me the wrong address. After that, being as completely irrational as I was, I began heading off to the beach with the full intention of drowning myself. My parents caught me on the way and managed to talk me out of it.
So. Seventeen and my first suicide attempt. Great.

 

Yeah... I'm trying to keep a grip, but it is so hard...