I am sorry to hear about your predicament. There are several things to think about, when you and your husband separated, what were the main issues? Who initiated the separation? When you reconciled, what were the conditions of the reunion? If you see recurring patterns, have you spoken to him about that?
There is nothing worse than feeling abandoned and alone in a marriage. I know from my own experience. It is a very painful experience.
The thing is, you can't change him. You can only change yourself. You can only control yourself. Therapy might be a great place to start, to figure out what it is you want, not just out of your relationship, but out of your life.
Once you determine what you want, then you can begin moving forward toward your best life.