Sara, Something just crossed my mind, it's just an idea.
It is obvious he is still in withdrawal from the OW and depressed. Sometimes when the withdrawal is too painful for them, MLCes try to contact the OW to alleviate that pain , "just to check if she is OK", specially if they had a deep emotional connection with OW and it lasted for a few months.
Once the contact is being reestablished their mood is back to what it used to be during the affair and they cannot stand their spouse anymore (nasty, spew, everything is good to be criticized they are looking at any excuses to blame us for the mood swings, because they know they are back to lying and they don't want us to ask any questions). Mine was like that. That's also how I knew "here we go again". He was blaming me , I couldn't be right, he had to make nasty comments on everything and he started to take all his meals alone away from us and rush to the bedroom. He became very secretive.
What makes me think that way, is that he voiced his intention to divorce you after you find a house you could afford ALONE. Did he ever try to persuade you to buy it together or bigger? I do remember he told you he will put the down payment, it might have been his way to fill less guilty about his intention of divorcing you, spending money that way could be a way to sweep the guilty/shame feeling he might have.
Why does he want to live with you until the divorce? Why does he not want to find a place of his own? Does he have the intention to leave your city, your state? If he is back with OW it might be easier to leave if he doesn't have a place of his own. Just ideas again... but they are something to explore.
Me 52+ WH 57+ Married 20 + Piecing since 2016 (ready to give up...)