Throwing a kid out is really a "sink or swim" situation. Some kids in that situation will swim for the first time; some will sink and drown. You really have no control at that point. (Not that you have very much now.)

If you can't help him, maybe if he's on his own, he will find somebody else who will. Or maybe he will find another enabler, or someone who will exploit him. It's really impossible to predict.

If you want to have ANY positive influence over the course of his future life, you need to get some help for yourself. Alanon is a good place to start. Look in the phone book. If it's not under "Alanon," try "Alcoholics Anonymous" for a referral to an Alanon group.