Sounds like the doctor is a jerk. it would have been stuck to the wound when you took it off as well, and he is quite more equipped to handle it than you are. what kind of dressing was it? wet to dry is supposed to stick. if not, try some telfa. take a deep breath, and give yourself a break. look at how you can do better, and don't take anything too terribly personally. people in this field seem to love to blame and pass the buck. be pro active and ask your manager if you can come in a few hours extra to learn the system better.