What should I do about this stupid english teacher?

Go into business for yourself teaching English. 10 pesos a lesson.

Respect her for trying. If her English is not good, she should probably not have been hired but who knows, there may have been a good reason. At the very least, as a student you should behave respectfully toward the position she holds. Did they hire you as teacher? No. She has the authority of teacher even if it is less than ideal. You could perhaps talk to a school counselor and see what could be done, but you had better watch out that you don't act like a little punk. People have very long memories, and many relatives who would be happy to teach you another kind of lesson someday.

be polite and helpful. "i always thought it was XXXXX... was i wrong all this time?" kind of thing. it gives her the chance to accept the help without losing authority in the class