No, it is not possible. And if the doctor really knew what he was doing and knew anything about mono he would not have given him a pill for it either. There is not cure for mono, and taking antibiotics only makes it worse. It is not transferred sexually. You can get it only from saliva, and it does not cause the symptoms your man has.
Also, mono symptoms wouldn't last for 2 years.
AJ
No, mono isn't an std, though you could certainly get it from someone you are having sex with. Mono is spread through saliva, mucous from the mouth or nose, and maybe in tears. I got mono from my biology lab partner in high school, and I assure you, I wasn't sleeping with him.
Mono wouldn't be causing the symptoms your man has, either. Mono would cause a sore throat, fatigue, swollen glands and a fever - not a rash on the genitals.
What pill did he give your man?
This sounds strange to me. Did the doctor even do a mono test?
Aj