trust is really hard to gain again once it's lost. It's not like you don't want to trust her anymore, but it's just that you can't bring yourself to do that. Giving yourselves some time away from this relationship should be a good thing.

is the guy friend still living with her? if that's the case; i doubt she's gonna stay persistant for long. She may end up lying to you about the truth or something. Or maybe not. At least she was being honest with you.

Take some time off and see if you can find another girl who is in your state, in your city. Long distance relationships are really hard to maintain... unless you go find her, and if she goes find you and stay there.
move on, and see if she can really show you what she meant.
perhaps when you move, you won't care anymore, or maybe you will, and forgive her.