Cheating..

My long distance boyfriend was cheating on me with multiple other people and one of them found out about me and contacted me. I flew out there to see him without him knowing I knew so I could talk to him about it and we could get past it bc I really love him..he tried to break up with me bc he said he can't trust me bc I didn't say anything the whole two weeks I knew about it and now nothing can be the same because all of our trust is gone. Somehow I managed to forgive him for all of this and I want to marry him...am I like completely retarded? Lol he seemed really genuine and sorry and promised he wouldn't do it again but now I'm scared he will when he is over seas (he is in the navy).. Oh and I was raped by an ex during the first month of our relationship and I didn't tell him it was rape bc I was like ashamed I guess..so when I finally did tell him he thought I was lying to cover up me cheating on him. So maybe that's why he did it bc I he thought I cheated first?