If you dream of yourself missing an appointment, you are not focusing and paying enough attention to the details of your life. You fear that you are not achieving your goals and that there may be many obstacles in your way that hindered you from keeping that appointment. You should try to live up to the expectations that you want for yourself and not others around you. Even if you did miss that appointment in your current awake self, it does not mean that the world is going to end. Try to reschedule if possible.