You will look back and be grateful that you ended it. He is not your project or problem to fix. You were only 11 months in and not financially/legally tied... you still have the chance to move on and find true happiness in a relationship.
Find an AlAnon group near you and get involved. You will learn a lot about this disease, and about yourself. You will also get a great deal of support on holding your boundaries with this A....there's still a chance he will try to contact you once the dust settles. If he does, the best advice is do NOT respond.