Old Man... that story is jaw dropping. I am not surprised you feel nervous. What that instructor did to a student pilot, just post solo is appalling. As FKiwi said - you did nothing wrong and should have nothing to do with a training outfit that allows that level of incompetence and complete lack of professionalism.
Flying is not meant to be like that. Find a school with an older, experienced instructor who loves teaching people to fly. Tell them your story and why you are nervous. You need good competent instruction to put that experience behind you. What was done to you was akin to an assault IMO. You were right to be scared. And with a passenger in the back... that could have easily have ended very nastily
No wonder you are nervous. Take it easy. There are cowboys out there but it is most definitely not the norm in aviation. Steer clear of cowboys.