Welcome to islandgirl and Kitty Tantrum! It's wonderful to have more ladies posting!
Kitty, this is one way in which the lack of guidance from parents is so devastating for girls/women. You would have been so much better off if your parents had gently helped you with the husband selection process. Not arranged marriage, of course, just helping you look over the prospects before you went so far as to fall in love. They may have noticed something off about your ex-husband that you missed because you were young and starry-eyed.
Whatever pain you went through, you got your sons from it. I'm sure it's hard to forgive your ex, but at least he gave you your sons. Having never been in your situation, I don't know if that helps. I hope so?
So far, I'm older than all you other ladies. (Early 40's.) I'm starting to feel a little mother henish.