Started On Diltiazem 180mg XT About Three Weeks Ago. Also

Started on diltiazem 180mg XT about three weeks ago. Also took amoxicillin for ear infection. I broke out in a very bad rash. Mostly on chest and abdomen. So I quit the amoxicillin about two weeks ago and took benadryl. The rash seemed to resolve somewhat. But here I am two weeks later and still seem to have some type of rash/ hives. Mostly chest and arms. Also a sore throat and face flushes occasionally especially when I have a heater on. Can this be related to the Carriage XT?