What Causes Burning Sensation In Throat While Swallowing?

I was discharged from the hospital on Monday after surgery from a bowel obstruction. I had the NG tube in me for 5 days. Since removal, my throat and tonsils have become worse. There is a burning sensation when I swallow and no matter what I eat. Hot or cold. I can not even tolerate ice cream. It BURNS. I was tested yesterday for Strep. It was negative. Yesterday I was put on Amoxicillin. Is this normal after surgery? The first day after the NG removal was not even this bad.