Definitely know what that feels like.
I spend hours on end about a month ago just trying to psych myself up to get it over with because it felt inevitable.
I typed myself a note on my iPod about how I couldn't go on and why, and just kept trying to dig myself deeper.
If it helps at all, I'm in a better place now. It didn't feel like I ever would be at the time, so it might not help, but I know what it feels like.
I got so bad that in the end I didn't care about fool proofing my plan, I was just tempted to hurl myself over 20 ft drops or walk into traffic, so I went into hospital.
If you have a decent support network hopefully it won't come to that for you. I've only got 2-3 people here at uni that are actually helpful, and even then, it's their
job to be helpful. I know they care, otherwise they wouldn't have the jobs that they do, but still.
I used that to distance myself from my first psychiatrist too... he said he'd be upset if I killed myself and I told him it was his job to be upset.
Kinda mean of me I guess, but I'm sure he'd heard worse (probably heard worse from me too
).