Thanks for your question.
Propranolol will block the physiological symptoms of anxiety and may be used for the treatment of situational/performance anxiety on an as-needed basis. Also as you are aware this will decrease your blood pressure, hence need to monitor the blood pressure when the medication is started for a few weeks to prevent dangerous low blood pressure. If this medication is giving you such strong adverse effects that are intolerable then you need to call your doctor again and inform him/her. He/she may then advice you to discontinue the medication and give another type of anti-anxiety medication which does not have this side effect.