Ping, Hi. I have been following your situation. I know you don't want to hear this, but I think you need to revisit one issue.
I think there is a big possibility of another man being in the picture. It is extremely rare in these situations that there isn't. Please don't put your head in the sand on this issue.
Do some more digging. Your situation is pointing to that in every direction. You need to find this out by doing some investigation work.
I know how hard this is to hear, but I have not seen any other poster encourage you to look into this possibility deeper. It is one of the most common patterns with a wayward spouse there is.