Ignore anyone who says you should go and teach anyway. You are not obligated. They have not had to pay for anything for you yet. You have the right to change your mind before you begin working without any problems. It is done all the time. In my last school, several teachers changed their minds before coming to Korea. No problem. Yes the school wants you to come, but you are not obligated until you begin working. They you have a contract to fulfill. Do not let anyone talk you into doing something you do not want to do. Changing one's mind is ok. We all do that at one time or another. My advice is not to get into something for a year or more that you are not committed to doing. That would be far worse. It is not too late. Tell the person, Riverina, that it is not despicable to change your mind. Let that person take your place if he/she wants to. Believe me, as an experienced teacher in several Asian countries, any reputable school would prefer not to have a teacher who is not fully committed to teaching at their school. One who is not committed will not do a good job. Make sure you are going because you want to, not out of guilt.