Hey, Someuser. Sorry you're feeling so bad right now. I think it might be time to go talk to someone or seek some help, especially if the anguish over this young lady is affecting your ability to function and to move on with your life. Sounds to me like the drugs and alcohol you've said you've resorted to in recent months are just making the problem worse, and it's not likely to get better on its own. A few sessions with a good counselor or even possibly a hypnotherapist can't hurt.

The thing you've got to break is the pattern of obsessing about this young lady. She's made a choice in another direction that she's going to have to stick with. And you have to work hard at not reinforcing the obsessive thoughts about her by continuing to think them. Everytime you go through the process of thinking about her and tormenting yourself about her, you help reinforce and strengthen that pattern in your mind. So to break that cycle and feel better, you've got to consciously start thinking other thoughts. That's not always easy, but I guarantee that when you do you'll begin to feel better.

Take a class. Get some exercise. Volunteer to help people who are less fortunate. Get out and cultivate new friendships and relationships, whether they interest you or not. The distractions and new stimulation will be good for you. That's why some counseling will help, too, to help you see what you're doing and how you're reinforcing your own sadness. Do everything you can to make a conscious effort not to keep brooding and obsessing about her.