Stay strong! I am so very sorry for the pain you are feeling right now, but THE very best thing you can do for yourself is stay strong and do not let yourself engage in his sob story when he contacts you, because he WILL say all the right things to suck you back in. It is what they do, instinctively. Please stay strong...come here for support.
As painful as this is right now, consider yourself lucky, blessed, that this has happened. You are not married to him and you can learn much from this about yourself and FOR yourself. Don't beat yourself up, you are not a fool. Addicts are exceptional liars.