There's a saying I heard a long time ago that still resonates with me today, "Hurt people hurt people."
As difficult as it seems, do try not to take your ex's actions personally. She is in the throes of something far bigger than herself, than you, than your relationship. The kind of pain that she is in is all-consuming and she is just grabbing on to whatever she can to try to escape it even for a little while--alcohol, you, drugs, other men. None of it is about you and how you treated her. It is entirely about her own pain and her trying to find a way to live with it. She obviously doesn't have the tools to deal with pain in a healthy way. You and her family are collateral damage in her misguided attempts to get right.
That being said, your post raises a lot of concern for me about your own sense of self-worth. You put up with a lot of terrible treatment, my friend. You gave a lot while only getting abuse and neglect in return. That's not what healthy relationships look like. You deserve a better partner than you settled for.