Had the same in April. Had a tonsil out and afterwards at the hospital and for a few hours after at home - I thought 'this is a breeze'. Then the meds wore off.
They insisted I eat proper food striaght away to ward off bacteria and infections in the mouth. Otherwise I would have lived off of ice cream. A meal would take 2 hours as each mouthful was agony and I had to grip the table to swallow. Certain foods set the wound off eg. non ripe bananas and Heinz thick soup. Had to take to my bed after trying these foods.