Itchy waxy ear and afraid of the vets

Hello My ten year old Staffordshire had always had a very itchy waxy right ear, we always treat it with the ear drops supplied by our vet. In the last three years he has become almost impossible to take to the vet even for his injections as he get so stressed and although not an aggressive dog in anyway does snap at the vet. He was due his booster in August this year and I have not taken him yet due to his distress. We have noticed however in the last two days he yelped a bit when scratching his ear we cleaned it again. He had surgery (with a different vet) three years ago for lumps on his back, thankfully benign. Dont know what to do for the best Thanks