trying hard to figure things out

[TrentC]

At this point I don't know if our M is worth saving. He barely communicated with me before and now that he has been caught I can't see him talking to me. He has always refused to deal with anything so I don't see him owning up to anything.

Well, given what you said about suspicions of infidelity throughout your marriage, I can see why he'd have a hard time dealing with this. (Not that it excuses his conduct; I just see bringing this up now as continuing a trend in your relationship of accusation and denial...)

Is there any point in me trying?

If his affair is truly a dealbreaker, then I would say "no, it's not worth it." Only you know where your limits are.

Should I try to contact him to talk about this new info

You mean accuse him of having an affair yet again? (And yes, I understand that he actually is, or was, having an affair, but hopefully you see my point...)

No, there is no point in contacting him about this info. Your best bet is to stay dark. Collect whatever evidence you have for the time when it will be necessary to bring it up.