I just want to give you a massive hug because it is so clearly coming through your words the amount of pain you are suffering. I’m so sorry you are still hurting.
This is PTSD and it is unearthing additional trauma for sure. As I was going through therapy post WH’s affair so much came out of my childhood trauma, my fear of abandonment, my lack of self love. And then, less than 3 years ago when my brother died, the trauma residues appeared again including everything caused by infidelity. I remember shouting at my husband (again, 3 years past dday at that point) "nobody values me, nobody cares about how I feel, how their actions would affect me, I mean absolutely nothing to anyone in my life" (for context, my brother’s death was self inflicted).
There is a lot to work through, I have been where you are for about 3 years solid (and for you it has been 5, it must be so exhausting). I reached a healing point, supported by my WH’s efforts to show he has absolutely nothing to hide, by therapy and by a lot of introspection, that reminded me this is not what life should be like.
I now know that something made me dig deep (almost) 7 years ago, no matter how much WH was gaslighting me at the time, I did not rest until I discovered his affair. And this was when I truly thought he was not capable of cheating.
I trust my gut fully now, I know that if it was sending me signals the first time around when in theory I trusted him 100%, now that I know he is capable of it, my gut will scream no doubt.
I hope you manage to work through your wounds, all of them, infidelity or not, and dig your way out from the hell that ptsd is.