Dont fret over it...no teacher would really EXPECT any student to memorize hundreds of pages for a play. Just chill, first of all. If you really have to do this play, then do it (for grades etc....cause truth be told plays in schools are just a waste of time...a huge one indeed). This will not make a single difference in your life, unless you like acting and want to pursue a career...otherwise find a way to skip it, cuz it is just a huge waste of time and effort...I am saying this because I have been in your place and have also been a teacher... Shakespeare is a good writer, dont point your anger towards him, but we would hate anything that is imposed to us. Plus these plays at schools always do the original no justice. I mean, if your teacher told you to study some math, some language or whatever else that would be useful for real life (say finance, or whatever adults need), ok, I would tell you to try a bit...but for a play...christ, dont even bother.