Broken again

Oh man, where do I even begin? I have been with my fiance for going on 4 years now. We own a home together, we have three kitty cats that I love so so much, we have built a very intertwined life. I am less than a year away from graduating nursing school, I'm an addict in recovery, and I am (in this moment( so confused and depressed. Throughout our relationship there have been multiple times where I have seen chats, videos, and photos on my fiances phone. We have gone round and round about it. Back in October it all came to a head. I saw he had asked a guy for *** and from that everything poured out. He told me everything that had gone on since we have been together. There has been no physical cheating, just virtual, so he says. He says it's an addiction and we started seeing a couples counselor and individual counselors. Things felt better, as if we were healing. Cut to Valentine's day I find that he has created a secret email address and has been using his work phone to access social porn platforms. One in particular he chatted with someone from his sexual past, asked if he had any videos of a particular guy, then also said he misses it sometimes (the old life style he lived) I confront him. He says it's not him seeking out someone from his past cause he misses them sexually, more so it makes him feel as if he is connected to that lifestyle without actively partaking in it. That don't make sense to me, because is you actively seek out someone from your sexual past for sexual purposes, then is it not that you are seeking sexual satisfaction from that? Almost reminiscing? Idk, that's it in a nutshell, but obviously there is much more. In all other aspects he is legit the perfect partner. All the qualities you'd want, but he can't seem to leave all sexual things aside and let it be between just us. I have sever trauma from multiple experiences like this from my past and it is definitely causing a trauma like response in me. Heart racing, headache, can't sleep, can't eat, stomach turning. He knows how it affects me and we BOTH agreed in the beginning that all sexual things would be kept between just he and I. So, here I sit alone and confused wondering what the *** do I do. Open to all suggestions, opinions, and advice.