Please, please, please slow down. Get someone else to take your daughter to the musical. You have absolutely no business attending such an event right after surgery. Call your dr, I am quite sure he will agree. Overdoing it will not speed your recovery, it will do the opposite. When your dr said to walk, its like walk in your neighborhood. Start with walking may be 2 houses from yours and slowly build up your endurance.
Do you have any idea the pressure that is placed on your back when you sit? Its a great deal. Are you planning on getting into a car and driving with you so fresh from surgery. I do feel that you did not get proper instructions from your dr on what to do and what not to do.
From what you described with the leg pain already gone it sounds very positive for a successful surgery, but over doing will only screw things up. A dr can only do so much in surgery, once you come home the ball is in your court. Be kind to your body. Hugs, Susie