Hi,
I lost my mum nearly 15 years ago to cancer and have only just let myself accept that I need to deal with it, so the fact that you're looking for support now is a great start.
Is coming home going to be easy? No, but it's where the people are that can offer you the best support, love.
What I can tell you is that in time your memories of how your dad was when you said goodbye will fade and instead you'll remember the happy, smiling father that made you the young lady you are. It's ok to smile when you remember him, just as it's ok for you to cry.
The best advise I can give (which took me nearly 15 years to accept) is to talk to those around you, tell them how you're feeling. You won't be the only one that feels the way you do, so draw strength together and support one another, in person over the summer and then by video chat or phonecall when you go back to work.
Matt