As a former (military) trainee and pilot who is now instructing in the civilian world, I have to say that being a good pilot goes not make you a good instructor. Some of my owrst experiences were at the hands of truly gifted pilot who just could not understand why I could not fly as well as I could. The best QFI I ever flew with could not fly a good barrel roll but did a fantastic job of teaching me to fly a good one!
The guys who struggled in their own training are usually appreciative of the difficulties that their trainees are experiencing. This understanding helps them to find a way around the problems.
However, if an instructor has a bad attitude it is usually because he is a frustrated fast jet or airkline pilot who is secretly a little embarrassed that he does not have a "better job" and works this ouit on those lower down the food chain.
Miss Biggles - ignore the git - ask on this forum for pointers to a school with highly regarded QFI's and go get back in the saddle. A good instructor will remind you that this IS the best fun you can have with your clothes on!