Hello and welcome. Thanks for sharing your concern. According to the history given by you I would like to suggest you few things. Nausea,dizziness and stomach pain could be due to stomach infection due to consumption of stale food products. Toothache is probably due decay.To confirm the diagnosis an x ray is required. Coming to intake of pain killers for arthritis,I would say please see your physician for correct dosage,as too much of any medication can lead to adverse effects on your vital organs like kidney,brain and heart.thus avoid self medication please. finally i would like to say visit your dentist first,get the tooth examined.your dentist might prescribe you antibiotics and necessary analgesics for three days. This will take care of other symptoms too. if you donot feel better even after taking prescribed medication then you can see your gastroenterologist for further help. Hope it helps. Thanks. Take care.