My Son Is 19 Yrs Old. Last Month He Was

My son is 19 yrs old. Last month he was in the hospital for 4 days with myo pericarditus. It appeared to be a viral infection that inflamed the outer area of his heart. He is quite healthy, slim, a second year engineering student....rarely I'll. He was sent home with aspirin, colchicine , and another medication to settle his stomach due to all the aspirin he was instructed to take. He got mono just before Christmas and now he has had a runny nose, clogged ear since a few days ago and now he has severe pain on his forehead and right eye. His jaw was sore on the weekend. He is tired very easily. This is so uncharacteristic of my son who used to be in good health and active. He has taken Tylenol for the pain and it helped earlier but now it doesn't. What could be going on?
Laura