It doesn't seem like you gave it enough time to work. Usually most meds like that take 2-3 weeks to start to work
Just to let you know, this isn't social anxiety, it's agoraphobia. Are you in therapy? Keep in mind that 3 days isn't enough for any effects to occur, though it is enough for side effects to occur. They might have gone away, and might have stayed for the duration, no way to tell, but any med you try is probably going to have at lease some unpleasant side effects if you metabolize it enough for it to work, and that the side effects will manifest long before the effects you want start to work.