Suggest Treatment For Sore Throat, Swollen Glands And Extreme Fatigue

Hello! I am 30 years old, and I was diagnosed with Mono about 6 weeks ago. I had all the symptoms....sore throat, swollen glands, extreme fatigue, etc. I drank plenty of fluids and got plenty of rest for several weeks, as my doctor put me off work. I returned to work this week feeling great....but now I am exhausted again. Is this common?? I feel like I could sleep all day....which is what I did for about 2 weeks straight when I was first diagnosed. It is very hot outside (98 degrees) and I thought maybe the heat had something to do with it. Just curious as to how long Mono will still in my system and when I will stop feeling this way. Thanks!