You are in a terrible situation. I think everyone has great advice. Woman shelter for abuse is a very good idea. As far as how do you leave since she is there all the time.. Like Riot said she has to go out at some point.. and I would assume she sleeps. Many women leave in the middle of the night, that is an option.

The one thing I would say is right now while you can go thru your personal belongings and decide what you want to take , say .. pictures or anything that means something to you. Pack a duffel bag with few changes of clothes whatever personal things and hide it. When and if you make the decision to leave you can grab it and go. It's a shame that you may need to do this to have a life on your own.. but abuse is abuse. You deserve to be safe.

Stay safe