PG - it sounds like your H is in a bad place right now. You need to focus on taking care of you. If you haven't, read Divorce Remedy. THere is a part on affairs. Read threads on here. There are people with experience re affairs.
Schedule a consultation (first one should be free) with a lawyer or two and learn about your rights. It will give you some peace of mind and a feeling of control over the situation. Doesn't mean you have to do anything - just gather knowledge.
He: WAH Me: LBW Precious: DD
~ I'm grateful for every day I have to improve the way I relate.