He's given me hardly any reason not to trust him. Unless you count whe we were dating about 3 weeks and I caught him checking out 2 servers using the reflection on the window next to me... Or unless you count the song that he wrote about his ex girlfriend 3 months into our relationship... The first song he EVER wrote and it ended up being about the girl he said he never was able to get over before me... Or if you count the fact that he had 2 females... One of which he had past sexual relations in his room sitting on his bed with him and another female a couple weeks into our relationship... Something he was honest about... Not honest about his relations with her until after that fact though...
Other than those moments we have had a wonderful 2 years together coming up on October 13th. He's been incredible always coming to my work to bring me food and take cig breaks with me. He spends so much time with me. We have a VERY healthy sex life... Maybe too healthy for 2 years of dating... But I can't get over my trust issues. I see he's added 2 new females to his facebook. One is a buddies girlfriend... The other I can not tell. He changed his picture from a pic of me and him to a pic of him...
Our relationship isn't rocky it's great. I love him and believe he loves me but when him and ANY other female are brought up in the same sentence my blood boils. It doesn't help that we are in a small town and he hasn't had the most innocent past before me. These girls used to love to approach him with wide arms every time we went out. They eventually got the hint.
I can't seem to get past the old things that had me upset. He called off our engagement. He said he had wanted it since February. We got engaged the beginning of August and he called it off about 3 weeks ago saying it was because of my trust. We were arguing a lot. We don't talk about getting married any more
With him taking back his desire to marry me, I think it's made the trust that much worse. I don't know how to control it. How to contain it and what to do! Please help

I don't want to push him even further but I always feel like I'm just killing time here waiting for him to move on to the next one. Like he's ready to leave at any given moment. How do I stop the feelings and thoughts?
He tore my heart apart breaking up the engagement. He doesn't know that. I thought we were perfect together. We would be perfect together. We are always so compatible... Agreeing on everything. Then one day he doesn't want to marry me any more. Some days I get "In 20 years we are going to do this" and other days I get "When you get older and buy a house... Then when I buy my house..."
Ugh!!! So confused and pained over this I just don't know what to do. If he called it off does that mean it's off forever?
How do I trust him when in reality he hasn't given me much reason not to trust him?!
I hate my thoughts sometimes!