Humans are irrational beings (lawls that's such a condescending thing to say). I personally seek instant gratification for many things I want.
I've had my share of bad days too, where I feel nothing is going right, where I might not even go into work because I can't get myself out of bed.
Every time I feel like "this is it, I'm going to do it", I do exactly what Dobby suggested.
Step back. Breathe.
I wait. I sleep. 99% of the time this was just a fleeting moment. After a day, maybe a week, I'm back to myself, and I tell myself:
"Hoo! Glad I didn't give into that single moment of weakness."
I always ask myself, if I were to be gone tomorrow, what would I miss?
And it's always the little things. I would miss watching Gintama (anime). I would miss calling friends up at 2am and getting a midnight snack.
There's a friggen' pile of games on my desk I haven't touched yet (I have to stop buying games).
You feel like you're a waste of space? That's fine. Nothing wrong with that. I feel that way sometimes too, and I just think that I should be selfish.
Sometimes I will grab a random friend (often its my best friend) and ask something completely selfish.
"Spend the day with me. Don't ask any questions."
Of course, he's like "wtf i have school but okay then." But he doesn't question me. He knows somethings up, but he doesn't know a single thing.
Find someone to bitch, to moan, to complain about all your problems. Have them babysit you.
If you don't have anyone like that, you're wrong.
We're here.