It's normal for you, what I mean by that is that only you can truly know how you feel about your experiences at the school. I can appreciate you want your parents to understand, but if you have explained it to them and they still don't then it might be that they never will. You are an adult now and as such you should not feel the need to justify your choices.

Bullying, and adults condoning of it, can make a real dent in our confidence into adulthood, so I don't think it's abnormal to not want to go back to that place - and if you have other options then plenty of reason not to go back.

It sounds like you have a real insight into what makes a good healthy educational experience, good luck in your career as school counsellor.