One of the symptoms of Mono is extreme fatigue. Also have you been tested for sleep apnea. When I saw my physician I was complaining about my fatigue. I told him, put me in the corner and I will be asleep in 10 minutes. He sent me for the Sleep test, and a man with an oxygen and Cpap machine were at my front door. I ask him why he was there and he told me "your doctor said we had to be here this morning. Your oxygen level dropped to 61% during the night". I have been on the machine and oxygen in the evenings ever since. The test is easy, you just have to sleep. You might ask your doctor about this
Gina5009