I found out my husband has been cheating...advice?

A month ago I found out my husband of 10 years has been cheating and he admitted it’s been going on for 2 years and still has contact with the other woman. He had begged me to stay and work it out but I can’t anymore since he won’t let her go because he needs some kind of plan to break off their relationship. I’m looking into getting a divorce but since I can’t afford to move out and the finances are kinda rough so I feel stuck right now until I figure everything out. He says he loves me and the kids but I don’t know about this marriage anymore. I feel he loves the other woman because he won’t stop contact with her. I’m so scared of becoming a single mom it’s difficult to process all this. Sorry for ranting but I need someone who can give me so much guidance.