A 36-year-old man presented to the outpatient with long standing history of fainting and blurred vision when travelling on bus. The symptoms are less when he travel by his wife's car. He avoids public transpo and is confined to home. At present his wife works and cooks for him. He does not leave home to shop or for enteainment. He describes to you that he has had some bad experiences of felling like his hea is racing, sweating and intense fear when he was at work. What is the most likely diagnosis?