Started taking propranalol 3 weeks ago for anxiety - have been taking 10mg tablet once or twice a day (as and when needed). This week I saw my gp as didn't feel they were doing much. She said I could take 20mg two or three times a day. I took 20mg once yesterday and twice today but feel more anxious than usual and want to stop taking them. Can I just stop or do I have to do this gradually?