Break up. Relationship

Hello I really need someone's help to understand what's happening in my life. I had boyfriend during 3 years. It was serious relationship. Problem is that we r from different cultures. He is Palestinian and we had huge cultural differences. I really loved him and love now too. It was my first love and for him same. Just during relationship I felt stressed because of this differences . He could ask me to wear covered clothes, to have distance with some boys, to not post that much of my pics on Instagram and so on I don't want to say everything. I was doing it because I loved him from heart and I really wanted to satisfy him. For him such things were important so I promised that I'll do my best but after some time it was getting harder and harder for me because as I said I'm from completely another society. Our problem was just this different he loved me truly and I was feeling it and I was trying to understand this cultural gap bug it was hard so after 3 years in this summer I told him to finish relationship. It was shock for both of us and it was hardest summer ever. But idk I kind of lost all Hope's that something can be changed, he was trying all summer to get me back (he was in his country at that time) but I was saying no, because during this period he could be kind and sweet and trying to fix everything one day and that suddenly became angry so I was losing Hope's more and more. I knew he is suffering to but idk how we could fix relationship. After several months one guy wrote me. He was liking me in past and my boyfriend new about it . When he wrote me again from the beginning I was against it because I'm not interested in relationship and I was stressed but than we started to talk. I told him that I still have feelings for my ex boyfriend and I don't want nothing. We were talking and at some point it went in another direction we were sending pics to each other wich I regret now to much and I hate it. I was really stressed and I was trying to find way to release it but I chose wrong way. Than my ex boyfriend came back to city and he wa strying to get me back we were comunicating normally. And one day I left my laptop and he opened it and so messages with that guy, he was shocked, really shocked and angry. It was biggest stress I have ever had in my life . He blocked me everywhere , after 1 month I called him to talk because idk, I was feeling guilty about it. We talked and he is really in pain now because he couldn't imagine that even we weren't officially together I could talk to someone else. I really love him more than anything but I felt so lost and so lonely idk how to explain everything together. With that guy I finished everything I told him that I dont have feelings towords him and I deleted everything but now my ex boyfriend is asking me to somehow find alredy deleted chat between me and that another guy and he wnats to see and read everything even though he saw some stuff by himself. He is saying that he needs closure, he needs to see everything and suffer some time and than let it go and he might forgive me and we can contine relationship. U know I feel so low , I don't think that like this u can forgive someone, if u want to forgive person it should come from heart. I'm really confused . I'm trying to explain to him that closure is in his head and we cant build healthy relationship if from the beginning u want to check this stuff. He loves me I know and I love him too but it's so complicated please help me I'm really lost and feeling alone .