I have ulcers in the mouth due to intake of antibiotics. Any quick remedy?

1.The Doctor has prescribed antibiotics for severe pain behind the left ear on the backside of my head. In the meantime, I have been having ulcers in the mouth due to intake of medicine and I am finding it difficult even to eat or drink. Pl suggest some quick and effective remedy. 2. Doctor says the ache behind the ear is due to impact of wax for which he has also prescribed ear drops containing antibiotic. Will there be any serious problem other than impact of wax?