I Have Tender Glands Under The Chin, Along The Armpit

I have tender glands under the chin, along the armpit area, 46 years old, blood test show positive for mono, I have a 12 year old and he has not been affected, so I question the results. Abdominal bloating 2 months straight, negative h pylori. Very tired, headaches, some abdominal cramping varies from right to left side. nauseous on a few occasions with glands producing a lot of saliva. Cannot eat much and no real connection with any certain foods. Any thoughts on what I should be checking for?