I got mono right after I graduated from high school
But aside from the sore throat, it wasn't that bad. I don't recall ever feeling exhausted. The only thing that concerned me was the enlarged spleen.
The sore throat was the worst. I had these white things on the back of my throat that looked like blisters. I could hardly swallow my own saliva, let alone solid food. The doc gave me prednizone (I think) and it seemed to disolve those blister things. I was eating within hours of the first pill.
But, if your sore throat has passed, you don't have much to worry about. Like others have said, just take it easy and don't over-exert yourself physically.