Try not to take Dom too personally. He has some excellent points. Self-examination is always difficult. (And yes, Dom, sometimes I think you take your own frustrations out in others' threads, too.)
That said...
I'd say one of your problems is that you keep bouncing back and forth between your xw and your gf. M not going well? You found OW. Wait, maybe that wasn't right...I'll go back to the M. Whoops, that fell apart...might as well go back to the gf.
I'm not saying you don't care about these people at all. But I hear more about you and your wants than what you've put either of these women through.
You need to pick a direction. I don't know what the right one is. It may be neither of these choices. And you may not know right away. (I'm still struggling on what the best thing to do is...) But the back-and-forth means you won't get anywhere, in the long run.
Relationships take effort. You have to choose to put that effort in.
He has some excellent points. Self-examination is always difficult. (And yes, Dom, sometimes I think you take your own frustrations out in others' threads, too.)