I feel responsible for my 5th grade teacher quitting her job
Why would you feel responsible for that?
Because I went to the principal to complain about her being so mean to me
I'm sorry that she quit her job. But if she was really being mean to her students, teaching probably wasn't a good career for her.
She was kinda mean sometimes.
Try not to feel like it was your fault that she quit. There could have been a myriad of reasons why she did it, I'm sure it wasn't just you.