Trouble trusting boyfriend

My boyfriend and I have been together for 1 year 8 months now. I'm still having trouble trusting him. He's gave me a million reasons for me to trust him. Even his friends told me he is the most faithful person they know. In my past relationships I've been cheated on many of times. When he goes out, I always ask him questions like "were there girls there? did they touch you? did u flirt with them?" It's tearing us apart. We both want to be together for the rest of our lives. We recently had a conversation about this whole trust issue and we almost broke up over it. He told me that if we have to have this conversation again its over. Please help, our relationship is a stake because of me. I want to be able to trust him, I just have a mental block in my head. I suppose I'm doing this to protect myself from getting hurt again. That's probably why I ask all those questions.

Thank you,
Kalena Lawson

Trust

Hi, I need some TRUTHFUL advice.
My girlfriend and I met 18 months ago and since then we have been living together for about a year. She has been married six times and has gotten a divorce every time. I have never been married or been in a truly serious relationship until now. We told each other all the things that two people say when they are passionately in love. We discussed everything in our lives with each other and made plans and decisions for a permanent relationship. I even gave up my job so we could work around hers, since her job was more established and secure. There are many other things that were discussed that I could include in this message but it would be too long.
Now, she wants to give up on this relationship without telling me all the TRUTHFUL reasons why. I expressed to her from the very beginning that her relationship track record was bad and that I was not looking for a serious relationship at the time that I met her, but the fact that we both agreed this relationship was for real and we could commit to it, we decided to RISK it.
My values are the most important thing to me and TRUST is at the very top of the list, which I expressed to her. How can someone be so cruel to fake a relationship, committment, and LOVE? She tells me that she will LOVE me forever, no matter what happens, but why should I believe her. She has already broken my TRUST. It's not the fact she has broken this trust that frustrates, it's the fact that I can't TRUST what she tells me anymore. Am I fighting a loosing battle? I hate to walk away from something that I put so much effort and sacrifice into. She has some serious isssues that she needs to work on, and we have discussed them, but for whatever reason, she wants to end the relationship.
By the way, she has wanted to end the relationship many times before only to change her mind. Not because she wanted to work on herself or the relationship, but because of the reasons that I still don't know. She has also left once only to call me and wanted to get back together. All of these actions are things that I'm analyzing and trying to come to a decision. There is much more that I could include but I'm hoping someone can give me some advice on what I've written. Thanks for all of your help.

- Mike