Re: verbal abuse from a teacher
'Old school discipline' or harsh training shouldn't make you feel as you describe. Abusive domination however does. It's for you to spot the difference for yourself. For you to learn how to say no as well as yes.
On the other side of the coin as you wish to be an uchideshi then it is to recognise honourably serving does not mean being subservient.
Bullying is the act of a coward. Much bravado, little courage.
I would say practice validating yourself, acknowledging yourself, patting yourself on the back and grant yourself the right to be. It starts with you to yourself. When you can handle yourself then he will be a oiece of cake.