Should I divorce?

My partner and I have been together for 9 years. During our boyfriend/girlfriend stage he cheated on me with his ex, I forgave him and stayed(it was just a kiss). I got married and left my country, went to another state and we were “happy”. I got pregnant, had a girl, almost died giving birth, got postpartum depression and anxiety as well. A year after my daughter was born, I found on his phone dick pics and vagina pics of him and another woman (they exchanged them). Why was I not enough? Two years later I met a guy, kissed here and there and now he says I DID WORST than him that he didn’t deserve this, that what he did to me its no excuse for me to do this. I didn’t cheat as revenge, but I hate myself for doing so. I asked him why he disrespected me so much and he told me “because I thought no matter what I did you would never leave”. I may add, he is a sweet guy, gentle, has never hit me, yelled at me or spoken ugly stuff to me. So consfused.... *please be gentle with replies*