Quote: "Don't worry, I am not and never have considered suicide. Quite the opposite. I don't expect this to last more than a few more weeks before I normalize again. And also the majority of the time I get over this by rerouting my thought process once it starts down this path."
I did something a bit like that. I decided to try and look at the universe in a cold, logical, objective light. So Earth became infinitesimal, and all human beings (myself included) became worthless and meaningless. After a while I stopped because it sort of got in the way of everything else, but I still think it's relevant.
Hmm... I sound like an emo...
But, though you can decide that life is meaningless - "why live?" - I think there's a lot of mileage in the question, "well, why shouldn't I make the most of it?" After all, I will die one day BUT if I kill myself today I'll miss out on a lot of interesting stuff, which would be a shame. Since dying today and dying in a hundred years' time will (I think) lead to the same result (ie. absolute nothingness and a complete lack of consciousness so I won't even experience it), I may as well live life to the full now because it'll all end up the same in the end but at least I'll have had fun.
I'm also intrigued in the idea of making yourself live past your own death. (No, not necromancy.) I mean leaving a mark of yourself: writing a book or making a work of art or (the 21st century option) making videogames. That way, I like to think that you'll sort of cheat death by extending your influence beyond when your heart stops beating.