Yes I Was Put On The Antibiotic Named Clindamycn Hal

Yes I was put on the antibiotic named clindamycn Hal 300 four times a day! It's my fifth day and everytime I try to eat, I swallow and when the food gets about half way down my chest, the pain is awful for a few seconds! Is this dangerous? I'm sorry I can't afford this, I didn't know it cost, but thank you very much!