What I do that helps me is this. I make a conscious effort of always having something to look forward to, I plan a night out at the theatre, or a lunch date with a friend, or a concert, and I pre-book these.
My down days and moments are bad, really really bad, and can be dangerous, so in order to 'get through' these tougher days, I remind myself that in a month I have arranged this other thing, so I have to wait till this tough time passes, and then I have something good around the corner to look forward to. (If that makes any sense to anyone other than me)
It's just a small trick that enables me to ride out the really tough days.
Wishing you all the strength you need to get through your tough days, and the same for you too Jamie, been reading your other posts, and my heart goes out to you. I couldn't comment at the time as I had two friends lose people this week, one to suicide, and one to natural causes, but was a sudden collapse at age 27. What I wanted to say, would have come out wrong, but you have been in my thoughts.