Hi,
Welcome to health care magic,
It would be slightly difficult to diagnose here in your case from only these symptoms like headache, body-ache,nausea, dizziness and
stomach upset.
However,it could be related to
stomach infection or acute
gastroenteritis but should be confirmed by appropriate investigations.
Also,It would be better if you can tell me any other past history of any disease or medication or surgery.
The possible causes I could suggest according to your age are
acute gastritis or indigestion or
tension headache or sinusitis or might ear problem.
You can go for routine blood investigations,ESR and urine with abdominal ultrasound.
Treatment is mainly based on the underlying cause. However you can take symptomatic treatment like,
pain killers (if cause is not gastritis),
antacids like ranitidine or pantoprazole or rabeprazole,
antihistamines like betahistine or cinnarizine.
If you still have not been relieved from the symptoms, then I would advise you to see your physician for detailed history and thoroughly clinical examination to get the diagnosis first.
Thanks and Regards,