When I was 15 years old, my best friend committed suicide. Actually, he was the only close friend I had at the time, and the only one I would make for many, many years. I was the last person he spoke to on the phone, and we spoke for four hours. Unfortunately, I didn't find out what happened afterward until several weeks later, when his mother called my mother and Mom broke the news. So I don't remember much of the conversation, and that has always haunted me.
To say that suicide is selfish and uncool is a dramatic understatement, and everyone who's ever contemplated or committed it has heard that one before, so I'll spare you. I will say, however, that while scars heal, they never fully stop hurting - even after (as of this month) seven years of the nightmare. I'm a fairly open, honest, high disclosure kind of person, and to this day I still hate talking about what happened to my friend, even with very close friends. I still have a hard time making those close friends because of the trip one of them laid on me seven years ago. I still get sick with grief on the anniversaries of his birth and death. And I'm still very, very angry that he stuck me (and his family, and his other friends, and anyone who tries to get close to me) with the emotional bill for what he happened to be going through.
But it's likely you've already thought about that, and you don't need another guilt trip. There's another, more practical reason for me to mention my old dead friend. I met him online (the other reason I never talk about him is I hate admitting I spent my adolescence on AOL) and when he placed his suicidal phone call to me, he was 3,000 miles away. And, I reiterate, I was 15 fucking years old. I spent a lot of time when I was younger trying to figure out what I could have done to help him - trying to figure out why I didn't hear the misery in his voice and what magic words I wasn't saying to fix his misery. (Words work for me. I reread the VERY ILLEGALLY POSTED "Last Thoughts on Woody Guthrie" everytime I'm feeling low.)
But for a person with depression as severe as his was and yours sounds, there probably aren't any magic words. And that means that people who are nothing more to you than text on a screen are not going to help you any more than I could help my friend when I was a voice on a phone. Whatever magic words we share with you might eventually wear off. The only thing I can really tell you is that you sound like you've been a lifelong sufferer of depression. And situational depression is extremely common in folks in their late teens, especially overachievers like yourself - and biological depression is going to be exacerbated when you face big life changes, which I think you do. So, you may not feel normal, but in that sense, you are. Lots of people go through this, and they come out clean on the other side. My life from ages to 18 to 20 was almost consistently a nightmare. But I woke up. Lots of other people have the same nightmare and they wake up and start feeling OK, too. Ask around. There is no reason that can't happen to you.
But noders, as kind and beautiful and loving and well-intentioned as most of us are, are not the people to make that happen. Dealing with depression is a long, long process. The people who can help you do that are the ones who are there for you on a day to day basis. Those would be your family and friends, and those are the people you need to talk to. They are the ones who can make sure you're taking good physical care of yourself (because, trust me, eating, sleeping and exercising on a regular schedule will help you keep your psychological strength), and they are the ones who can help you figure out how much professional help you need, and your doctors can help you figure out whether drugs will help you or not. Your friends and family will be there to talk to if you find yourself in crisis. The people who are part of your daily life are the ones who can help you straighten things out and feel more normal, by helping you change your routine. Noders are not. Frankly, a lot of us are psychological fuckups, and listening to such characters is kind of counterindicated. And the circumstances do not exist for the stable, good-hearted folks in our number to help you. We can't take you out to coffee and listen to you talk - and even then, we're not as connected to you emotionally as your friends are, so that conversation is less likely to make a difference.
I know the anonymity factor is a big part of why it's tempting to bring such feelings here. But if you really want the pain to end, you're going to have to be brave and ask for help from the people who actually stand to help you. They're going to be somewhat frighened and worried, and you probably hate to do that to them, but you sound like you care about yourself and the people around you enough to cut your damn losses. Scaring your friends and family now is going to work a whole lot better than scarring them later.
Best of luck to you -