I Was Bitten Or Stung By Something In Florida Yesterday.

I was bitten or stung by something in Florida yesterday. Began as a warm poke. Barely noticed. Just below erist. Back to the car put hand sanatizer on it and drove an hour. Iced and elevated. Slowly worse and worse. Took benedryl. Hour later redness creeping up arm. Went emergency room. Got a shot of prendizone, told to keep ice. Prescription of oral prendizone for 5 days. Continue benedryl. In morning seemed better. Took medication iced a bit. Flew home to michigan. As day went on more itching redness and slight swelling moving up arms. Now can't sleep. Redness now to elbow and itching worse. Suggestions?