You must ALWAYS follow the advice of your doctor. Hypnotherapy is considered to be an "adjunct" therapy. That is, it is designed to compliment the services of your doctor or mental health advisor, not overrule them.
If you become aware of a conflict, inform me right away so that I can correct my approach to better align with the wishes of your doctor or even ask to speak with your doctor to make sure we are "on the same page".
The instructions of a medical doctor or mental health professional must always override those of your hypnotherapist, up to and including the discontinuation of the use of hypnosis.