Relationship problems what should I do?

Hello there, I have big problems in my relationship. I worry that I am making things worse, but I don't know what else to do. I will start from the beginning. Initially, I found out that my boyfriend had a whole folder of naked pictures of different girls he knew personally, each sorted in folders with their names. He even had pictures of one of my old friends I had a falling out with. The problem I have with this is that the pictures he had of her were ones in which she had just given birth to her baby. In these pictures (I guess unknowingly to her), one breast is partially showing. I find the whole folder idea disgusting anyway, but how can you save pictures for sexual enjoyment in which a woman is holding her baby? it just seems very sick to me. To clarify, I don't have a problem with porn, just find it strange and odd that someone would have literally thousands of pictures of girls they know in various states of undress. It gets worse. I stupidly sent him some pictures of me because he kept bugging me about it. Thankfully they did not have my face visible. He sent these pictures to one of his friends. Also, I caught him talking sexually to other girls over facebook and passing pictures with them back and forth. I have found accounts for adult friend finder and okcupid, which he has deleted. I had a long distance realtionship with him for a while and we would skype a lot. I was changing shirts and jokingly told him not to save this on a video. I later found the video saved on his computer! Anyway, my question is how do I trust him again? all of these things happened a couple of months ago, but they still continue to bug me. I know this man does love me. He does do sweet things for me, like buying me flowers and dinner, and I feel awful because I bring up my distrust of him sometimes (not just out of the blue, but for example, I did bring up the previously mentioned falling out friend's pictures when he mentioned how cute she was in my high school yearbook). I hate being this way, I am not this kind of girl. I often feel sick with worry and guilty at the same time because I want to forget about it all but don't know how. Can someone give me any advice on this matter? is this relationship even salvagable? Thank you!

He got the pictures off her facebook. She had posted some pictures on her profile of the new baby, and I have to assume she didn't see it in the pictures right away. They were taken down and cropped very soon after that. I have talked to him about it, and as far as I know, he has stopped, but I can't help but worry that he is just getting better at hiding it. He works with computers and is very tech savvy, so I feel it would be very easy for him to hide things from me if he wanted to. My struggle is the fact that I do not trust him anymore, and am not sure how to build trust with him again. I feel terrible, because I feel like bringing it up at this point is just "stirring" and really isn't doing either me or him any good. I am unable to stop feeling hurt about this though, and wonder if there is any way I can possibly get over this betrayal of my trust.

Your relationship is like all others, it needs trust as its foundation. If you don't trust your BF and have difficulty accepting his behavior which prevents you from trusting him, then you are better off without him. Forget about the sweet things he does, it's the other things he's doing and has done which confuse and turn you off of him. You know your values and standards and now you have discovered what your BF's are to a certain extent. It's your decision whether you stay and deal with it or you walk away and deal with it. One thing you need to understand is that your BF has only made changes to his behavior after you have discovered the results of it and you're correct..he'll most certainly only get better at hiding it.