I assume you've got a method set out?
What you're facing right now is the worst enemy of all of us. It's your survival instinct - and it isn't easy to overcome, no matter how miserable you are. There are certain ways to overcome your survival instinct though. When you're going to jump for example, count 3...2...1...0 in your head, but jump at 2. Little tricks like this can help you. I've also read that alcohol makes everything easier, but I don't think you should get drunk as that would just ruin your attempt.