For what its worth, my W gave me the "personalities don't match" and "you just need to be ok with me leaving" speeches too. There is a website where you can take an enneagram personality test online for $10 (good stuff by the way, worth doing to better understand how you operate and what drives you). She took the test, figured out my type, then told me all the ways we weren't compatible. When I went to the site myself, there was a whole other list of how our types compliment and benefit each other that she had just ignored. The bottom line is that there is no such thing as incompatible personality types, every combination has both problems and benefits. This is just another "I want to have my affair" justification and you can safely ignore it. You can't change your personality type anyway, only how you operate within it. Your type is why H chose you to begin with.
The "you need to be ok" is H's plea to release him from the guilt. They want to think of you as happy without them because it makes their lives so much easier. My W actually also gave me the "If you love someone set them free" speech, that just made me think of the song.
As for ow, yes she is doing something very very wrong getting involved with the H of a married women with small kids. Its terrible and reprehensible but there's not much to be done about it other than to rise above.
What I learned is that there is power in granting their wish to "be ok". He feels responsible for your feelings right now because you've made it clear that he is denying you happiness. That casts a black cloud over your head when he thinks of you. He doesn't want to be responsible for how you feel. Feeling that way makes you unattractive compared to happy go lucky OW. If you truly seem OK, then he will wonder why and that will bother him and draw him in, and sharing in your happiness will once again seem attractive.
As painful as it is, the best thing you can do is give him up for now and make it your mission to meet new friends and have fun. Tick some things off your bucket list. Make sure he takes the kids enough to allow you to get out and have fun. Shoot for 50/50. The best thing that can happen is for him to call you and hear music and fun voices in the background. If that happens and he wants to know what's going on, just say you're out having fun and provide no further details.
Accuray
Married 18, Together 20, Now Divorced M: 48, W: 50, D: 18, S: 16, D: 12 Bomb Dropped (EA, D): 7/13/11 Start Reconcile: 8/15/11 Bomb Dropped (EA, D): 5/1/2014 (Divorced) In a New Relationship: 3/2015