Feeling quite horrible today, terrible headache, malaise, watery diarrhea...seems to have subsided. Am I okay to go to class tomorrow. No fever?

Probably. If your symptoms have subsided and you are not running a fever you should be ok to go to classes. Be vigilant about good hygiene- especially washing your hands. You may find that you tire more easily since you have been ill, but that should improve steadily once you are back on your feet.
Yes. As long as you don't have a fever you should be fine to attend class. Take hand sanitizer with you and drink plenty of fluids.