Change instructor. You are flying for pleasure and there is no reason why it should not be fun; certainly enjoyable. It sounds like this miserable sod is making your flying unpleasant. A proper instructor will show you respect. They will allow you to gain confidence as you learn and a really good one will inject humour into the process. Yes, there are many items that you need to be serious about (lookout, speed/s, engine management, location) but that also can be accomplished in a civilised manner.
...don't forget the margin for bank angles.
Banking will not change the useable fuel in the tanks. Slipping and pitch changes will.
Don't give in. Use your towel to flick the guy's arse on the way out!
PM