My elder sister is so meann.....she is a torture in my brain...please help?

My elder sister was out for office...i had to rush for water to the owner when i was alone in home..because the tank was empty...i mistakely wore her shoes and went to the owner..so i didnt travel a semi half km even coz the owner stayed in the same building where we stay.. and then after some time she came back and got to her notice that i had wore her sandals...she came vigourously to me almost attacking me....she said me that since i wore her shoes i had to wash her shoes ..i was cleaning vessels in the sink...she kept her shoes in the sink not allowing me to wash those vessels...i said i shall wash the shoes for her after sometime...and i wore because i was in a hurry...she didn't want to wait and she snatched my fone when i had an incoming message...i told her to give the phone..she said she will only give when i wash her shoes properly...she stood in front of me waiting to watch me cleaning her shoes..i took her shoes in the bathroom washed it with detergent powder and gave it back to her.....after some time her boyfriend came....and probably her boyfriend gave her those sandals...so i heard her saying to him that" she had wore my sandals so i made her wash the sandals very nicely".........after hearing this i felt she had been treating me like her servant...she otherwise could have said i had told to wash her my sandals..which shows more decency ....there is a lott more about her.. this is not the only one torture she gave me till now....she doesn't even allow me to drink water that she kept in the fridge..if i had drank from her bottle mistakenly...bottles must be separate in our house...if i drink...then she would use abusive languages or attack me..or take money for the bottles.....what should i do....??? i am scared to react to her,,,she is so heavy looking...she can almost burry me....