Betrayal...it is a hard thing to deal with.   D fallout...another hard thing to deal with.   Dealing with them at the same time...SUCKS!!!!!!   I am still learning to handle it all.  It has been 1 1/2 years since I found out about the affair and the D.   It has NOT been easy, but through both individual and couples counseling, we are in a much better place.   We still have bad times, but as he is working to control his D, things are improving.   It is possible.  We have had many talks about why it happened, and he really has no other answer other than he wasn't thinking clearly and he screwed up.  NO KIDDING!!!   But the fact of the matter is, that within a week or so of starting on antidepressants, he ended things with her.  (I found out after the fact.)  So I figure there must be something to what he was saying.   He said that it had nothing to do with needing to feel something, but had everything to do with the fact that he couldn't see through the fog of the D.  When he got on the meds and started to see more clearly, he realized what he had done.  It DOES NOT excuse what he had done, but it explains a lot.  

What I have learned through this board, is that infidelity during D is not an uncommon occurrence.  The pain has not gone away, but has lessened.  And, the trust has not fully been restored...we are at about 75% restored.  (I still get nervous every time he texts or is on Facebook.)  But, with hard work, the relationship can be saved...if you both want it to be saved.  It is not an easy road.  I think that divorce would have been the easier road, but not necessarily the better one.  Not that divorce is easy, but with divorce you end it and can work on moving on with your life.   To REALLY fix the relationship takes a LOT of hard work and it is often painful work.  In the end...I am happy with my choice.

Dig down deep and figure out what it is you really want.   Either way, you have people here who are willing to support you.  Good luck and lots of hugs to you!