You may be dehydrated. You need to be drinking water, juices, 7 ups, sprites, gatorade, etc. Try that. Dehydration will cause a headache and dizziness. Hang in there. Just drink, drink drink,
what you need is good long rest. you sound like you could have a fever and a tummy bug. the tummy bug usually goes within 2 weeks and it can be passed from one person to the next. you need to drink more fluids and rest alot more. to help with the pain clean and tidy your house and do odd jobs around it like doing the washing. then you wont feel so stressed out and worried about what you have to do. take a warm relaxing bath with bath salts and bubbles, also listen to some calm relaxing and quiet music while you are in the bath. then put a bowl on your bedroom windowsill or bedside table. put into it some scented oils and lavender or rose. make your bedroom as dark as possible then get into bed and take a painkiller if you are over sixteen such as anadin or anadin extra. if not then take paracetomol with codine. if it does not go within the next few days then go to see your doctor. i hope you get better soon. good luck on the exams.