There is a path we can take, and it can set you free. Your friend is evidence of it.
As I think about people in A's.... can you imagine being married to someone that cheated on their partner to be with you? That in itself would really make me question their character no matter how much I loved them.
I just can't imagine a relationship feeling pure and sacred when it was founded upon deceit, betrayal, and breaking someone else's heart.
Broke, you are taking the high road. And the high road is always the hardest road to take. But at the end of that road, is your freedom and I believe, true serenity.
I honestly don't think your H will experience serenity if he stays on his current path. The universe doesn't work that way.
Keep on GAL'ing, keep on 180'ing, keep on challenging yourself, and keep on pushing yourself out of your comfort zone. You're going to be ok, I know it.