Hey Neo,
I've got the same kind of self-destructive personality and it's damn near killed me, so I'm trying now to change it, for fear of allowing it to ultimately put me in a pine box buried in pauper's field.
I think you've hit on a solution that helps me alot and that's when I can get out of myself just enough to feel a little gratitude for the gifts I have in life. Being thankful for what I do have takes my mind off stressing over the things I don't. Once again, it's fleeting, so I need constant reminders, my short-term memory must've been fried years ago, lol.
Also, it doesn't hurt to start planning the next big outing to have some fun. Me, I'm literally going to Disneyland for the Holiday Spectacular, (as they call it, lol). It's only a couple hours drive for me, and since I'm still a kid a heart, it seems like the perfect place to celebrate a day of rides, food and fun. No booze allowed!! I'm taking my brother, who doesn't drink, just to help me learn how to have some fun sober. Planning fun is something I have to work at, cause I substituted booze for fun for years and now wouldn't know a good time sober if it snuck up on me and slapped me silly, lol.