I highly suspect he has a OW but could never obtain proof no matter how hard I tried.
What makes you think that?
I understand you feeling sulky and depressed. It's normal. But now is the time to really take a look at the big picture and what is happening. It's good that you told him you won't tolerate living together as "friends" until your kids turn 18. That is not fair to either of you. Him acting incredulous about your response to that is not right.
Take Puppy's advice -- on or the other.
In the interim, I'd recommend starting to look for a job. STAT.
