"I'm trying to take the line of 'its OK, take your space, gather your thoughts, it's important and I won't put pressure on you'
I'm trying not to cry, not to shout, not to beg, threat, put timescales on anything. "
Oh, God. Castaway, I really feel for you but STOP doing the Pick Me dance. It won't make him respect you, it won't make him fall back in love with you, it'll just eat away at what little self-esteem he's already left you with. I'm furious on your behalf.
Of course he's back with OW.
I know it's hard but you have to get tough. Tell him he's not welcome back, that your marriage is over and start making plans for the future without him.
Make him see what he's lost by his horrible, selfish actions.
Oh, and when I finally booted my cheating husband to the kerb, you know what? I started getting over it. Seriously, I feel so much lighter and happier now I'm single. I never have to worry about what or who he's doing. It takes time but I literally don't care. I'm free.
I wish you all the best.