Lend a sympathy ear please!!! someone who been in this situation or who's going/been there in this situation?

I have experience with this type of situation. I myself am a recovering addict. Your ex is suffering with a disease that effects his mind, body and spirit. until he really makes a decision to stop using drugs and face his life as it is, he will never be good for anyone, especially himself. If you are willing to put your life on hold indefinately, then do without regrets. If not, I suggest that you accept the fact that you cannot fight his demon and move on with your own life.