I agree that perhaps a new instructor might be in order but out of curiosity, how long have you been in training and are you flying with a buddy box?

Reason I'm asking is that if you're not on a buddy box, perhaps the instructor doesn't want you to get tooooo slow only to find himself not able to "grab" the plane before, well, you know.

Of course on the other hand, if you are on a buddy box, tell the instructor you are having difficulty. Let him know that flying at that speed is making things difficult for you to keep up with. If he continues to insist, find someone else to help you. Then, tell this guy thank you but you just weren't up to his challange. No harm.......no foul.

It's important to learn slow flight characteristics of your plane.

Hope that is of some help. Good luck and enjoy your flying. It's the only way!