I would think that it is only natural to cry and would urge you to let your feelings out – keep crying but know that you can still keep in touch. If the friendship is worth it’s weight then you will be fine…we have to let people go…it’s one of the greatest gifts we can give those we love to enable them to fulfill their dreams. But that doesn’t mean you can’t be sad… give yourself some time and love xx
Don’t make them feel guilty for going. It is okay to be sad and they are sad too I bet and will miss you. I know I am especially miss my best friend as I am out of the country for a year.
Remember that with email, text, Skype, you can stay in touch. Is this for a semester, a year, the rest of her life?
When I was young, I moved a lot, and it was hard to leave friends. But I always made a point of promising to write. When she is gone, you’ll be sad, but write her actual letters that you can mail, once a week, to catch her up on things. Eventually, you will still miss her but your life will adjust, and it won’t be so sad.