so angry!!

Hi,
I've been a lurker forawhile, but I haven't posted. Soo... here's my dilemma..

My boyfriend and I have been together for 3 years... we were planning on getting married, I was shopping for my wedding dress, picking out my ring, and even dining halls. (I'm only 22 by the way, he's 23) but throughout our entire relationship we've always had issues with his phone.

1st incidient: (8 months)
I always wrote them off as maybe I was being a little too jealous. But he would always carry his phone with him, he would never leave me alone with the phone, he took it in the shower with him, when he went to the bathroom, even when he went into the kitchen to cook. It was weird, and throughout our 3 years it never stopped. But whenever I would look at the phone I would find girls numbers in his phone. He said his cousin put numbers in his phone.. and since I didn't like his cousins (because they have done and said really shady things to me) I believed him. After that.. I had issues with a girl being in his house. He said the girl was for his cousin.. but I always found something weird about that, since he called me 6x that day to let me know EXACTLY what he was doing.. and how he repeatedly told me I shouldn't come over. I called the house phone, this girl answered and said they had been dating for a year... I asked him about it, and he was like, the girl was for his cousin.

2nd incident: (1st year)
We were still trying to work things out, and then some girl got ahold of my number and began prank calling me. She said this my boyfriend was her man, and that I wasn't the only girl he was with.

3rd incident: (1st year)
Some girl comes up to my sister (she was a girl who we had went to school with and we were all friends) and said to my sister that "Ashley should be careful, josh has been known to go out with more than one girl." So, of course my sister told me, and I went up there to talk to the girl and she said, "j has always been dating more than one girl at a time. I'd be careful. I'm not telling you want to do.. but my friend who dated him had to deal with what you're going thru."

4th incident: (2nd year)
I found a ton of nearly naked girls pictures in his phone. He blamed it on his cousins.

5h incident: (3rd year)
I found text messages with him and another girl. I called the girl, she said they had been going out for a year. He and I were practically living together at this point. He told my parents he wanted to marry me, and asked for their permission, etc. And she said, that when she saw my name in his phone, she asked him who I was and i was only "just a friend." He told me not to believe her because women lie. But I did, and asked her if she could send me a picture of them together. SHE DID. I sent him the pic, he first denied he was in it. Denied that he knew her. Then said, it was a pic taken a long time ago.

So, after this.. i broke up with him. But I still talk to him..am I justified in breaking up with him? I just don't know why I can't let go.. But I know the feelings I used to have with him aren't there for him. There's this guy in my criminal justice class, that I really do like.. but for some reason despite everything I don't want to let go of my ex boyfriend. what do I do?
Sorry for it being so long!

Ashley