I have been dealing with a toothache for moths and have taken a lot of OTC pain medicines, now I have daily migraines, nausea, vomitting and diarreah?

Stop OTC meds. Over use of otc medications could be causing a lot of your problems. Excessive use of Aspirin advil and Motrin can cause stomach upset and ulcers. Over use if tylenol (acetaminophen) can cause liver damage. Stop using pain medication to mask your problem and get to the dentist and have this problem addressed properly asap.
Chance or ? It is not impossible that at least 3 of the 4 symptoms are related to your tooth issue. If headache is "sided" and on same side as bad tooth, even more so. Over use of pain meds can worsen some headaches as well. Really should get tooth addressed to remove it from equation, then see if other symptoms resolve or if need dr eval. Good luck!
See a doctor ASAP. The number of severe complications and their potential for very negative outcomes should prompt you to go to a doctor or an er right away. Dental or periodontal infections can spread to the brain and other areas. Go and be evaluated immediately. Hope you feel better soon.