Trusting problem - please help!

I'm 20 years old and have been in a relationship with my boyfriend for 3 years this May. We have been dating since senior year of high school, although we both admitted that we liked each other in junior high which was before he moved to another state. He moved back senior year, and we got together. Now, at 2 years, we are living together in the same house. We had been living in an apartment with my sister until we moved to a smaller town. Now, we live by ourselves. Last summer, after being in this house for a few months, I was 'snooping' on my boyfriend's old phone. He called it snooping, but he had funny videos and pictures that I wanted to look at, seriously, that was it. I was looking at it and found a video. It was him and his ex-girlfriend on Skype. Three months prior he had told me she had sent him naked pictures during our senior year while we were together. I was upset that he didn't tell me earlier, but I let it go because he said that he got her to stop, and I forgot about it. Anyways, I tried to read what they were writing, but I couldn't make it out. So, I just watched the video. Before I got to the end, my boyfriend got off work (it was my day off) and met me at the park where I was watching it. When he saw I had his phone, he got angry. I asked him why he got angry, and he said it was because I was snooping through his stuff. He told me to hand it over, but I didn't. I told him that if we are to marry, like we both have talked about, that there can be no secrets. He can look through my phone, and I get to look through his. He knew that already because I set that rule before we ever got together. I kept watching it, ignoring the cold looks he was giving me. (I was swinging; he was sitting on a bench.) I got to a part where her camera moved off her and then when it moved back, the tanktop she was wearing was off and the only thing covering her top was white covers. He yanked it from me, and walked over to the merry go round. I sat in the swing. I didn't want to believe what I saw; I didn't want to know what was going to come. Eventually, I walked over to him and asked what happened after that part. I asked if she was naked. He said she was. He said that he tricked her into showing him her breasts so he can send it to her father and that would stop her from sending him anymore naked pictures. He said it worked because she got into big trouble. The problem? He did it on my laptop, in our room in the apartment, when I was at work, and he said he would have never told me if I hadn't found it! We got into a fight, and I walked back to our house, which wasn't even a half mile away. We got into another fight in September. He was texting a girl who was his ex, and I asked him a year BEFORE to please not text her again. He said he wouldn't. I saw his phone, though, as a message popped up and it said her name. I pretended I didn't know and asked who texted him. He lied and said it was one of his friends. I told him I knew it was a lie, and he said that he did it because he's tired of me always asking to see his phone after that Skype incident. I did start asking to see his phone, but I was scared he would do it again. I know that's wrong of me, but he's the first and only boyfriend I have ever said 'I love you' to. Plus, he was my second boyfriend, and I already had trust issues from the first in junior high when he dumped me because my breasts weren't big. He knew that, too, and said he wouldn't mind. So, I walked out of the house and around the road for a bit not replying to his texts so I can let out steam. We made up, again. (Out of place: The summer after high school before he moved into the apartments, because we were supposed to move together, he went on a trip with his stepdad which was only supposed to last a week. It lasted a month, AND we were supposed to have moved in two weeks prior. I moved in and asked when he is going to come up. Turns out, he doesn't want to because he's afraid because of how he used to act at his old school which was in a city. He did move in three months later, but he broke a promise and I can't trust people who keep breaking my promises!) Two months ago, I was on his Facebook, and he knew I was because I asked, and saw he was in a group that had naked pictures and videos of women. I got upset. He said he didn't do it. A month later, there were saved videos of naked women hidden on his Facebook. Found those and got into another fight because he didn't even know how to save videos, so he didn't do it. He said it was one of his friends who was probably playing a prank, but neither of us could see any of his friends doing that. Now, I'm just so scared he's gonna cheat on me. (There is a lot more to the story like how he let a girl who looked like his ex flirt with him in high school and flirted back even though I told him to STOP TALKING TO HER!, the fact when I went over to his house in high school, he would ditch me to hang out with his stepdad leaving me there alone til nine at night when my parents would pick me up, about to agree to a person at his work to sleep with her because his old habits popped up-he didn't agree thankfully-, and flirting with a girl at a party so I ended up leaving while he stayed.) I do love him a lot, I really do. I've liked him since junior high, but I've loved him since junior year, but I am scared he is going to watch/look at naked pictures of women. I'm scared it's because I won't have sex with him until we are married, although he said he thought it is honorable of me to do that. He said he doesn't care about sex. I don't know what to do. Am I just too paranoid? Do I need to let those past things go? He won't even text me like he used to when he is on break. Instead, he talks to an old 'friend' on Facebook. He doesn't seem like he even wants to be around me anymore... I really need help because I've never told anyone of these things, but when I almost did, I lost a friend because he had a crush on me and I wouldn't dump my boyfriend for him. I just don't want someone who knows who we are to say anything because everyone has a different opinion on him and me. My sister doesn't like him, but I've never liked any of her boyfriends, my mom says he stretches the truth and exaggerates, and my dad likes him as long as he don't hurt me. I would really appreciate any advice!

Firstly, regardless of what he says, you need to look at all of his actions. Never mind what your family think of him, it's you who needs to see him for what and who he really is. His actions are telling you that he doesn't have the need to be with you, never mind you marrying him. You need to realize that you have to have trust to have any sort of a relationship and this trust shouldn't be given lightly and it must be earned, not expected. You also need to understand that you don't seek to control your relationship and it's not the done thing to tell your BF who he can talk to and who he can't. Instead, it should be a given that he respects you, that way you won't have to dictate to him. You basically have no right to look at his phone just because you laid down the terms of no secrets, rather, if your guy shared your values and standards, you wouldn't need to. Likewise, your actions of just taking his phone without asking undermines any sort of respect and courtesy which is A foundation of any successful relationship. Long term marriages thrive on respect for one another and this respect is demonstrated by actions. Your challenge is to be with someone who shares everything that you need to have a successful relationship and respects your wish of no sex until marriage. Your other challenge is to let go of your insecurities because while you have them, you will always find relationships a hard slog. It's not so much about people breaking YOUR promises, it's about you surrounding yourself with people who don't have to make promises to earn your respect.