First of all: Don't be ashamed of your suicidal thoughts. That's like being ashamed of having an allergic rash or something. It's not your fault. If anything, the people who put you in this place should be ashamed.
Anyways. You remind me of a friend of mine. When I first met her we were being suicidal and self-destructive PTSD sufferers together. It helped us both to have someone who just listens and understands and isn't scared of the things you think or tries to preach or shame you into something. On this forum there's dozens of people who'll do that for you, listen to you and make you feel less 'outside' or 'defective' or 'failing'.
My friend was pretty much on the road to becoming an alcoholic, was fed up with her life, failing at uni, sleepless, this close to jumping etc. I don't know how she managed to take this turn, but about half a year later she got it into her head that, after other people made her into a wreck, she now wants to make that wreck into something worth her while (and that is: a bundle of pure muscle and physical stamina).
We're not talking much currently, but last time I heard from her she dropped out of uni (she'd been wanting to do this for ages but social pressure made her hesitate), is holding down a fulltime job serving drinks in a bar at the railway station (which she loves) and her goal is to get her six pack to finally show so that she can start a job as a workout coach. From the outside her life looks more run-down than ever, but really she's managed to build a sober life that she enjoys living ~90% of the time.
I don't know, maybe this makes sense to you. If life sucks, find your own way of living it and identify something that you're good at, something that you'd like to achieve/learn/master/..., something worthy that you can make of yourself, and make that the reason to keep going. And even if you don't think it works like this, what do you have to lose by giving it a try? You can still kill yourself tomorrow, or next week, or whenever :)
My reason for living are the novels I write. There are always days when I think that they're crap and I'm crap and why do I even bother?, but I know that there are also days when my work makes me feel good, productive and worthy. And knowing that those days exist helps.
EDIT: It's patchwork, sure, one good day here, one good moment there, but in the end it'll still be a blanket, hehe.