David,
I'm glad to hear that you're back at school! Your energy level will keep getting better the more active you are. Just take it easy at first.
You might want to contact your surgeon's office about
the pain you're having. They might want to check it out just to make sure everything's okay. It might be scar tissue (adhesions), which is common after any type of abdominal surgery.
Take care, and have fun!
Cecilia