I have to take revenge from my bullying elder sister..please help?

my bullying elder sister keeps on talking craps about my boyfriend just because she cant stand my relationship...and infact "her boyfriend" once said that he could sell my dad in streets.....i hate her really badd......she gets into my nerves.. every time with small things..i dont even talk to her...coz i dont want a fight in house....or negative energies everywhere...i cant fight the way she does...she is soo heavyy and she can beat me and tear me into pieces...she charges money from me for every small thing...if i drank water from her bottle mistakenly or say if i unknowingly ate her noodles worth 10 rs...she would charge me 10 rs even...i know she is very cheap minded girll.....and her boyfriend too is....they both chit chat about other people and their lives.......its really ridiculous.....and moreover she talks about my boyfriend....i tell you guys a fact...my boyfriend never even had spoken a word to her....still she says craps about my boyfriend...she spits on his name...whenever she wants to torture me...she even pulls my hair and kicks me in my belly...slaps me....beats me with kitchen rolling pins.....i am really sick of staying with her.....but my boyfriend still says that i need to respect her...i cant say him the things she talk about him..coz he wil really feel bad..i want to take revenge from her....please help me.