When did you start taking Propranolol
20 mg? Side effects of propranolol
include abdominal cramps, diarrhea, constipation, fatigue
, insomnia, nausea, depression, memory loss, fever, lightheadedness, slow heart rate, low blood pressure, cold extremities, sore throat, and shortness of breath( ref: http://www.medicinenet.com/propranolol/page2.htm). It is possible that your symptoms are related to the medication you are taking.