14 YEAR OLD BOY SICK OVER MONTH

My 14 year old son has been sick for over a month. He has been in the hospital out of the hospital, positive for lyme then negative, high liver emysems, low cbc count. One minute he is sick the next he is fine. He runs a fever then its gone, his pulse jumps real high, and blood pressue low. Right now he was at the hospital cause the kid looked like he was going to die, and he was in so much pain in his head back and neck. The pain is the only thing that stays, everything else will return to normal and then back down hill he will go. He vomits bile. Can someone please if you have been having through this please write me back, They have all done all blood test they can. I dont know what elese to do. He is working with a speacialist to see if they can help. My son was always healthy till this point. It all started on September 1st. He has alrady missed so much school, and what ever he has we know its not contagiouse cause he is the only one with it. Also a new symptom is that he gets a rash and his eyes turn all red, u cant see no white and the rash will cover his body then go away just as fast as it came. He has not been on any new meds, nothing new with food.