First, you need to stop snooping. You have already confirmed there is OW. Until your H tells you otherwise, assume that OW is still in the picture. Just because you stop snooping does not mean that you are turning a blind eye. Believe me, your H knows that you do not approve of the A. Unfortunately, he just does not care.
I completely understand where you are coming from. I drove myself crazy trying to figure out if H was still talking to OW, if they were talking a lot (looking at H's phone bills), if they were eating together, etc. When I finally let go of this behavior, I felt free. Do I feel any better about the A? No, it still hurts and I feel like I am punched in the gut every time I think about it for more than a minute. But I stopped torturing myself. It does not mean that you are okay with it.
I know that you dont want your H to be involved with the OW. And you said that you boundary is the OW. But what does that mean? If the OW is in the picture, .......? This is what you need to figure out.
