Zoe, go home and make him do the work.
If the OW is more important he will have to decide which life is going to live.
This isn't up to you and he has done this before Zoe, your young start again with someone who doesn't want to keep hurting you.
Once an affair has been between a couple the questions of what is really true is always there, I am 9 years out and I still question if he stayed for me or because he got caught. He does everything right but in my head I know he didn't want the affair to end.
So are you plan B or C.....
You don't have children by the looks of it, go take care of yourself
He doesn't deserve you.
The best way is to let the affair live in the truth and see what it really is.
He wants both of you and that is all he trying to get back to, don't believe anything he says you can see when ask a question he lies, it won't stop.
good luck Zoe....