Self-analysis - is there any rationale behind your thoughts? If you can pull yourself out of the bowels of misery long enough to think (it's hard, trust me), why do you feel the way you feel? There's always a good chance that there's a more serious disorder lurking, so
don't take this to mean that you shouldn't see someone. Don't discount psychologists just because they sometimes follow quack theories, either. Sometimes, just having someone to talk to is enough.
The dangerous threshold you cross is when you jump from extremely graphic, horrifying thoughts to physical activities that motion you on towards suicide. Once you, for example, start driving to a point where you want to jump off from or shopping for antihistamines to keep poison in your system, you're beyond the point where self-help can be effective.
I've been through this, and despite all the points where you tell yourself you're just going to do it, you reach a moment of mental clarity where you truly internalize the notion of suicide. You'll either push forward and decide to go on with it, or you'll realize that you just feel like shit and suicide is your pre-programmed pattern of thought for coping with it. If you decide on the former, stop and call emergency services so someone can save you from yourself.
This advice isn't pulled out my ass, either. I wake up every other day or so with the desire to crash my car into the local river or hang myself. But after thinking it through, I know it's because I have a shitty, non-relevant job and attend a crappy school in a backwater state in a country full of and run by ignorant loons. Just rationalizing my emotions removes the stinging pain that makes me want to kill myself, although I still feel the desire to bulldoze everyone in my local Wal-mart, so go figure. (-;
If you have a preferred contact method, let me know. I'd be happy to talk to you. Although I AM NOT A DOCTOR, NOR A DECENT SUBSTITUTE FOR ONE, I have been through something like this, so I may be able to provide more insight.
Take care.