Sorry to hear of your conflict. I am also one of those gentle souls. IMO he feels very bad, disappointed, and feels like a failure right out of rehab. I wouldn't yell or scream at him. I would sit down as calmly as possible and make suggestions as to how he can get hold of himself. I agree with everyone else. He has to want it himself!
I know you must be frustrated but all you can do at this point is get help for yourself. If he wants your help he has to ask for it. I know he must be sorry for the relapse. He just can't find his way out right now. Show him your love and give him the consequences if he doesn't stop. My best advice.
Best Wishes to you!