I very rarely post as I don't spend much time on this forum, but this thread caught my eye.
Look, hun, you sound in a really bad way. A lot of people confuse being a bit down with clinical depression, there's a huge difference and I'd hazard a guess you either are, or are on your way to the latter.
Get to your GP. If your GP is useless, see another. Do not stop until you've got a referral to a decent counsellor. I don't know if you need anti-depressants, but they may help.
I speak from experience. I didn't go to my GP until I was suicidal. I had to have psychiatric nurses visit me multiple times a day in my own home to keep me out of hospital. I can't tell you it made me better, because it turned out I was undiagnosed bipolar (a manic depressive) and flicked over into mania during crisis treatment. Anyway, the crisis team did do their job in that they delayed what was an inevitable suicide.
The point is that I'm making is that you don't want to wait until things are that bad. Admittedly, I have a very different illness, but if I'd seen my GP about my depressional periods earlier, my illness might have been caught when it was in a much milder stage.
You're already feeling suicidal some of the time. This is a huge warning sign. Get help. When you're depressed as hell, you believe nothing can help, but trust me, it can. There's so many different treatments out there. Give it a go. When you're suicidal, you have nothing to lose. You can afford to hang on a few days, weeks, whatever because death is such a final solution.
Give yourself the chance to get better.
(And yes, I am ignoring the drinking because it is a coping strategy. People with mental illness are fabulous at ignoring their problems and self medicating. Been there, done that.)
Keep posting and let us know how you get on, yeah?