I have the same problems with trust, when people tell you, talk to me when your down and then they turn your back, it's hard to trust again.
I haven't started this yet, but in my depression group they suggest writing your problems into a journal, that way you're releasing what is bothering you without having to talk to anyone. Or the other idea is get a box, write your problem on a piece of paper then put that paper in the box, and hope you can release the problems that way. As far as getting excite about your upcoming event, you may get excited as it get closer, or maybe not but just try to have a good time.