What Should I Do When I See My Love Leaving !?

Here’s the deal I like my friend , I really like her , Saturday is the last day to see her ever she is traveling to Australia and she doesn’t feels the same as I do . Saturday is the graduation day and the last day to see her , I don’t know how to act and how to say goodbye and what should I do ? she doesn’t feels the same towards me as I do , and she is leaving , so the main idea is how should I act when she says goodbye when I know that’s the person that I love the most is leaving forever , should I kiss her , hug her .. please need help in this issue I am desperate !