I have mono and need some help please

Hi, I'm 14 and was diagnosed with mono about 2 weeks ago. Had a terrible sore throat with really swollen glands which is what caused me to go to the doctors after being sick on and off for two months before i was diagnosed with mono. A blood test and swabbing of the throat confirmed I definitley have mono. I was put on steroids for six days which made me feel better and now my sore throat is gone. Then after my sore throat and swollen glands were gone, i still couldn't breathe through my nose because of congestion. So then I was put on a Z pac because I also had a sinus infection, and now I'm on my last day of the Z pac. So I'm almost completley feeling fine except a little bit of fatigue and small cough. My concern is that the extreme fatigue hasn't hit me at all yet. Almost every case of mono that I read about, everyone has had that extreme fatigue. Now I'm not sure if it's supposed to start soon, or if my mono is gone. I'm kind of getting tired of sitting around doing nothing all day because I have the title of mono on me. So if the fatigue part is supposed to come soon, I kind of want to know. Where if I'm not going to experience this state of fatigue, then I want to get back into exercising. So my question is, Will I soon be encountering this extreme state of fatigue? Or can I get back into exercising? (I did a 20 min. Fast walk today on the treadmill and my back was hurting all day, so I don't know if that means anything?)
Please help me, I am very confused and need answers. Thank you for any help!:) Tweet