If you choose to stay with him and hope to have good health yourself you're going to need to learn to detach. Focus on yourself. Let go. But, you may not be able to do that and find that the best solution is to end the relationship before it drives you crazy. It's impossible to "manage" his addiction. If he wants to use badly enough, he'll find a way. Addicts can be amazingly resourceful. Addiction is cunning. Take the best of care of yourself.