I didn't even know this thread existed... This is a great thread and hope people find some sort of salvation from it.
I suffer from depression (although I am a lot better than 18 months ago), my uncle took his own life 16 years ago after he found out his wife had Leukaemia, my mum attempted suicide a year before that (and is still on medication now unfortunately).
For what it's worth, only advise I could ever give anyone is to get to a councillor as soon as possible, and while you wait, talk to a close friend or family member. Talking it out may have taken me 2-3 years to get to where I am now, and to a lot of the issues I didn't even know were issues, but it was worth it