Everything you listed seems like a really bad combination, especially LD relationship + trust issues. My ex and I were in the same situation you mentioned (we only lived about 2hrs apart though). She liked to be with other guys and seek acceptance and always wanted to party/club with them. Ended up cheating on me. I would suggest putting boundaries for him/her, but that just may make the other person blame you for their unhappiness. Didn't work for me, maybe it will for you? I don't know how someone can just begin to trust someone though. Seems like something you should just let go. I'm sure there's someone else out there for you that's looking for the same thing.