Honestly, stick up for yourself. I have always had social anxiety and sticking up for myself has always been hard on me. But I was in a similar situation to yours. My trainer/BO was the same way, and finally one day, I had had enough. I wasn't rude, but I was straight forward. And from that day forward, I've been a lot better at sticking up for myself, and she wasn't that way with me anymore.
And there isn't any reason to be afraid of talking to her. The worst she can do is get mad. Tell her how you feel, and I"m sure she would understand. And, if you can afford it, ask her if she would sell him.
I hope this helps :)