Whenever i see my sister i want to beat her up. She has made my life hell, i even tried to kill myself three times and this was one of the big reasons to why i wanted to end it. She uses our dog with diabetes for attention, she steals everything from me including medicine for my depression. She recently moved back and now that im better i value my life enough to want to beat her up. I wont do this but she has no time but to play with my feelings. Her mood is massively unstable so if i confront her she WILL do things to ruin me, like blackmail me. 
What should i do? I’ll admit it im a pussy, but im workin all the time so i just go home crying tired. I cant get a break anywhere.