What Causes Recurrent Body Pain And Sore Throat After Taking Clindamycin?

Last week I had to have a root canal over a root canal. I was having pain in my cheek, not really the tooth. The endodontist prescribed clindamycin, which I have never taken before. The first night I had severe heartburn with it. The next night, I started experiencing body aches, joint pain and a scratchy throat. I went to the Urgent Care and the doctor there tested me for strep, which was negative. He prescribed a z pack to take after I finished the clindamycin if I needed it. Two days ago, I had insomnia, middle right back pain and severe pain in my joints. Today, I thought I felt better this morning. I contacted the endodontist who told me to discontinue the clindamycin. Now I have body aches again, sore throat and sneezing. Is this all from an allergic reaction to the antibiotic or something else now?? I never get sick. I can t even remember the last time I had a common cold. I feel awful and now I m getting scared.