Dog training question.

I use a shock coller fence and correction coller. With the fence coller he only shocked himself once and it was completely my fault. I trained him with the tone mode. And he would hear the tone and stop. Well I had him where I could take his collar off and he would follow me to the shop or wherever. Well one day I had my hands full and forgot to remove his collar and he just followed me. I heard him start waleing I felt so bad about it. To this day he won't follow me to the shop I have to carry him lol