I'd be frustrated to the max, too. I definitely don't think anything is wrong with YOUR emotions in this case! My son tells me about mistakes his teachers make. I even went into an English classroom one time and noticed that the teacher had used improper grammar on a poster on the wall!

Alas, changing schools from one state to the next, etc. can lead to the kinds of difficulties you mentioned. Having to repeat stuff is bad enough, but that incompetent teacher is really appalling!