How to cut a friend off.

I've been friends with this girl for quite a while but everytime were together something just doesn't sit right. It's as if she doesn't like me. She's very forceful and I think she went through my bag when I got up to go to the toilet. I couldn't find my lip gloss when I sat back down but when I got up and left I found it again.

Please I need help, how do I stop this toxic friendship my stomach just hurts thinking about it?