I too left my BF after 3 1/2 yrs of him running from his past...
If he called me today and tried to take advantage of me again by dumping his issues in my lap; I would gently remind him that although I would always consider him my friend, Friendship means honesty and Honestly, he needs professional help. He is being very unfair to his "new soon to be ex" and of course to himself.
Obviously, he counts on your compassion to be able to pop back up into your life after 2 yrs of nothing, but that certainly does not give him the right to do so.
You must think of yourself and the life you now live. Remember how hard it was to try and repair your heart after the break up?
I know I would want to do the "right thing" too, however, that is very different for both of you. He needs to face his demons and get on with his recovery (or begin it). You are in your own recovery (2 yrs now) and I would pray that your compassion does not jeopardize all the good work you've done for yourself. Grab a book on co-dependence and see if this doesn't spark some recognition....Amazing how many partners are affected!!! I know you loved this man very much...he obviously believed it too, BUT
email him the site link, the name of a few good books and wish him success in the future with his new soon to be ex.
THEN GIVE THIS MAN TO GOD and let the miracle begin.
My prayers are so with you now...Be strong..

"Insanity is doing the same thing over and over, and expecting different results."

I cannot take your steps, but I can walk beside you, if you'll let me.