Hi, and welcome to SR.
Sorry you are in such pain. If it makes you feel any better, addiction is something nobody asks for--my bet is that he didn't set out to lie to you and his family, to steal from them and break your heart. But that is what addiction does to people. As much pain as you're in now, you would be in a lot more pain if you were still in a relationship with him.
On the positive side for him, living in a shelter and bagging groceries may be just what he needs for right now. Most alcoholics and addicts have to suffer quite a bit as a result of their addictions to get to the point where they are ready to quit.
What do YOU need and want out of life? The more energy you put into living your life, the less you will have to spend on regrets for the past.