Just going to work where men are there also has been a problem so I think open relationship is out. Its like (I dont want you and I dont want anyone else to want you either).
Then why remain? Time to move on imo. (If kids are an issue, take it from one who was once a kid with unhappily married parents, they should have split years earlier and might have met better second partners if they had. Both ended and are ending their years alone.)