Please get another FNAC done after the course of antibiotics. Also, please ask your doctor and confirm that swelling behind the ear also seems clinically to be a lymphadenopathy
. In case the second FNAC is also reactive and is from a good pathologist, please rest assured as many a times the swellings in neck are reactive lymphnodes
. Please get a complete head & neck examination done by an ENT and also the dental examination. In case all are normal, the swellings will reduce in few days. In case you are still worried, get a CECT neck done. Regards.