You seem to understand accurately that, except in the instance of medical emergency, the doctor-patient relationship is entirely voluntary. It is impossible to know, of course, what was meant by "personal" reasons, but you must be aware that in the pain-management care every doctor is alert to drug habituation problems with narcotic pain medications. The answer to your case will be to travel a little farther for treatment.
Best wishes for an outcome you can accept, and please remember to designate a best answer.
This answer is offered as a public service for general information only and may not be relied upon as legal advice.