Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern...
As per your complain in case if you have pain in a single tooth then the cause of toothache does not seems to be due to headache but the headache seems to be due toothache as
radiating pain from an infected tooth can cause pain in side of head..
Feeling of tiredness and nausea can be due to
Septicemia and Bacteremia as the infection from tooth can enter blood and cause generalized tiredness as well as at times fever..
You should
consult a dentist and get evaluated and get an x Ray of the offending tooth done and get treated accordingly by either
root canal treatment or extraction depending upon condition of tooth..
In case if it is not the cause consult your treating physician and get your Blood Pressure and
Haemoglobin checked and the treatment can be planned accordingly..
As of now you can take Advil for pain relief..
Hope this information helps..