Last Night I Experienced A Rapid Onset Severe Pain Headache,

Last night I experienced a rapid onset severe pain headache, stomach pain, and extreme anxiety. I have been taking vitamins and probiotics to improve my health and I have not taken any Tylenol or Ibuprofen for about 9 months. Or any other medication for that matter. But I felt so terrible I took two Benadryl and two Tylenol and eventually fell asleep after about three hours. This morning I woke up after 8 hrs of sleep still feeling very tired and still having stomach pain. I slept another few hours and got up still tired but went to work. I ate some yogurt and granola and green tea for breakfast. My intense anxiety and stomach pain began again but only lasted two hours before it went away. It has not returned this evening.
I am concerned that something is out of balance with the supplements I'm taking, causing these headaches, stomach distress, and anxiety. (The headaches and stomach distress have been happening occasionally over the last month.) I am not prone to any of these symptoms normally and am completely healthy. I stopped taking all supplements last night and scheduled a dr appt for tomorrow afternoon. Are there any tests that might help me figure out what is causing these symptoms, especially the headaches and anxiety? The stomach distress is mild. Perhaps there are hormonal issues? Maybe my thyroid? I should add that I have been following dr. Perlmutter's advice and have practically cut grains out of my diet as well as processed foods and sugar for almost a year.