Don't blame anyone. Not yourself, not your husband, not even OW (even though all of us would prefer to bean our OW with cherry pies). Your H was just vulnerable, stupid, and decided he wasn't happy, and needed to make changes. You keep working on being a fabulous woman regardless of what he says or does, and wish him happiness (even though we all know eventually he's going to wake up and want to chew his arm off for how stupid he was... oh well...).
Take care sweetie. You are too valuable.
There is no arriving, ever. It is all a continual becoming.