What I think is an emotional affair and what do I do now?

My husband and I have been married almost 17 years. About a year ago things really started getting rough in our marriage. He was upset over my manipulation and control and I became upset over his (I thought inappropriate) friendship with another woman. We had many arguments and he decided we should do some sort of a separation. Since then, he has continued to separate himself more and more from me, and is currently planning to move into a camper trailer. I very much want our marriage to be healed but last I knew, he feels very ok with his friendship with this other woman and feel hopeless about our marriage. I so need wisdom on how to be able to heal, whether to take a stand on if he wants a separation then he needs to really separate instead of sticking around, or to try to totally leave him to make his own decisions in his own time. I have drawn very close to God during this time. If it wasn’t for Him I don’t know how I could still be hanging in there.