What could these symptoms be from? Diarrhea aching headache dizzy.?!

I've had these symptoms for the last 2 and a half days now. I've had to take time off school due to it and I have missed a very important Exam. My Mother originally thought it could of been meningitis but luckily the rash never showed up. I am now very curios to what it is. I have a dislike of bright lights, the top of my eyes hurt, a quite bad headache, aching all over especially in the neck and back, shooting pains running thought me now and again, not liking any foods but sweeter items, being extremely weak, lovely watery diarrhea and being very off balance. I do not think it is food poisoning as I have not eaten any bad food. I have been extremely hot even without the radiators on. I have had a high temperature to. I am also aware my science teachers son had similar symptoms and a 33 degree temperature. Is anybody able to shade some light on what is wrong and what I should do?