Quit apologizing to H and stand up for yourself. Your feelings are not crazy. You have every reason to be hurt and angry. H should not be seeing PW in the context of a committed R. He should not be endorsing her having another A. He should not be involved with someone who hurt your M. H's unwillingness to be direct with you is pretty gross. Those words you heard from H: "you shouldn't have to stay away from people who were part of your life" are VERY LIKELY straight out of PWs mouth. Probably how she guilted him into meeting new BF. If you wonder if she is being a destructive force in your M, the answer is yes.
You say setting boundaries has backfired. But you have not set boundaries. You keep trying to get H to change what he is doing. Boundaries are about YOU and what you will or will not accept.
H guilting you with the "I do so much to make you happy" crap is that -- CRAP. He should do what he wants to do. If that includes an inappropriate friendship with PW, sobeit. It is his choice. He does not get to martyr himself and then use it as an excuse for piss poor behavior.
Are you going to accept that friendship?
Maybe you two can go to MC to work on this issue. Or, if you don't have a C, find one to discuss your boundary issues here.
At some point, you have to take care of yourself. This is obviously a very unhealthy sitch for you. You need to do what it will take to make it a healthy sitch. Maybe this is simply stepping the R back a few notches, who knows. But, burying your head in the sand and then not liking what you see when you pull it out is not going to help.
