To be honest I never got along with teachers, like you, I kind of hit a plateau after a couple of years, so I went to a very well regarded bass teacher, I quit after one lesson, he made me play his way, he made me wear my bass at a certain height, rest my thumb in a paticular place, attack the strings in a certain way, I may be biased, but there was nothing wrong with my technique before that, i never had any physical problems because of my technique, never couldn't play anything beacuse of my technique, but he insisted his was the only way, I quit and never looked back, to me self taught is the only way to go, but everyones different