In my opinion, it is almost impossible to recover a marriage as long as there are more than two participants.
Your gut feeling is that your wife is seeing someone else sexually. That is then highly likely.
If you want to make real progress in recovering your marriage, your wife will need to dump the affair before you invest much into the relationship.
I am glad you have custody. It would be a good idea to make that legal custody if you haven't already.
Sorry I could not offer much in the way of encouragement.
-NOPkins-
I will ferret out an affair at any opportunity.
-An affair is the embodiment of entitlement, fueled by resentment and lack of respect. -An infidel will remain unreachable so long as their sense of entitlement exceeds their ability to reason.