Suggest Treatment For Migraine Headaches And Fatigue

My son 11 years old had viral menegitis in August, he was so sick and take to ER. Then shortly after he contracted mono. since then he s getting constant migraine headache. we had him tested for everything:MRI was normal vision was good, in short nothing was found, he s a healthy boy. As a result, his neurologist decided to treat him with over the counter pain killer for now. But then he starts showing the same symptom he had in Summer a few days ago:joint pain, sudden fatigue, headache, loss of appetite. My theory is maybe he did not really have mono in August after meningitis, nonetheless the blood work was tested positive for Mono? I understand they symptom can linger or can be chronicle in some case but he s looking like he is sick from mono for the very first time. I have talked to my local pediatrics so many times, their suggestion was nothing but giving him a home rest. It saddens me to see this active child so sick for over three month and barely keeping up with his life.