Death

I won't go into details, but I've been through a similar experience. Umm. I really don't know what to say that's going to fix anything. Except that one day, the first thought acknowledging that the worst is over will occur to you after having felt that way for a while. When that happens, I think you'll find it will be within your power to steer yourself away from unhappy thoughts. And you must be firm with yourself - you need to start reconstructing your life, catching up with where you should have been, staying away from self-pity and whatnots. Grief is something to do, and when it's over you should find things to fill the space that those thoughts used to occupy.

And be strong. Don't be emo about it. It sounds insensitive, I know, but I've been there. Emotions are useful - but when they're over, don't sustain the feeling, you're only being insincere and unhelpful to yourself. Also people you can talk endlessly about your thoughts without having to fear you're boring them or weirding them out are incredibly helpful, but not absolutely necessary. Just be sure to have some constructive outlet for your feelings.

Hope that helps.

Jam it back in, in the dark.