You sound like you are where Saffie and I were a few months ago when we both came to this board. Here are links to our threads from that time. I think they speak to the issue you are dealing with.
Since we were talking about the same thing at the same time, we did more of the talk on Saffie's thread, but I think there's a lot of good stuff on both of them.
Has your H returned or is he still with OW? Are you in piecing or trying to deal with the infidelity and rejection?