Help! Skin Rash

Tosha • Mother of one expires Dec 24th, 2017!
Hey everyone. Yesterday I went to the doctor for a sore throat and she gave me a Zithromax (zpac) for tonsillitis. Well is never taken it before but because I never had a history of drug allergies she thought it would be ok. So I took it yesterday and super early this morning when I got up to put my daughter on the bus. I went back to bed and when I woke up again a couple hours later, I noticed blisters all over my feet and a few anal ones on my hands. I immediately thought allergic reaction and called the Dr. She switched my meds to something I've taken before and told me to take the other one again (duh) but didn't do anything about the blisters. I assume figuring they will go away as soon as the old meds leave my body. Throughout the day tho I've gotten more and more of them all over. Up my arms, on my legs, a couple on my ears and face... Only the ones on my feet and palms hurt but it's weirding me out. I took benadryl to help counteract it but it isn't really helping. I'm trying you avoid going to the hospital. Any tips of battling this annoying reaction? My Dr didn't seem concerned as I called the minute I noticed instead of waiting. Would really like advice tho.