I think this is about you feeling out of control. If you can convince yourself that you are the only one that you can control 100% (which is the truth) then you'll be able to relax knowing that it doesn't matter how much you obsess about what she may be up to, how much you don't trust her and how much you cling, there is absolutely nothing you could do or can do to stop any of the things you've got going on in your mind that aren't happening but, you think they are.
You need to keep busy and hang with friends, do things that you put off because you spend all your time with the gf and didn't get them done. Have some kind of a life outside of her and her only which isn't healthy. Learn to trust.
A month and half will soon be over and in the meantime you can keep in touch through skype/email and phone.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion