Teen son has night sweats almost every night and is not eating (when he does he vomits) he is loosing so much weight i am really worried about 3 mths?

Needs thorough eval: What you are describing is not normal. Your son may have a serious illness or condition that needs complete evaluation. This isn't a couple day flu or a couple day fever. These symptoms are concerning. I would not run to the er tonight, but i definitely would make a call to his doctor first thing monday mroning and insist on an appointment within 1-2 days. God bless and good luck!