a few days ago, my fiance was diagnosed with strep throat and was given a shot of penicillin. now, he's having other symptoms. he's having postnasal drip, he has a headache in the back of his head, and he's having trouble breathing. his throat hurts worse than when he went to the doctor and he can't swallow anything. the drainage is so bad that he's gagging on it. he can't sleep because of it. he says he can't blow his nose. like, it's just draining down the back of his throat. i've never seen him this sick and i don't know what else to tell him. please help!