Stomach cramping/pain, diarrhea, nausea since yesterday morning. Today I also started getting body aches. I have flu shot. Is there anything I can do?

Stomach virus. It sounds like you've picked up a stomach virus a.K.A. Viral gastroenteritis and it's completely unrelated to the flu shot. You can take an otc diarrhea medicine like loperamide or pepto bismol (bismuth subsalicylate) to help and make sure to drink plenty of fluids, gatorade, and eat very lightly - bananas, rice, applesauce, and toast - nothing heavy or spicy to let your stomach rest.