Toxic Friend or Not

So I have a friend and she keeps annoying me in class. She will constantly touch my hand or grab something of mine to get my attention. No matter how much I would say no or please stop she would continue doing it. I put my head down for a minute and she put a squirt of lotion on my hand to get me up. I feel like if I don’t pay attention to her constantly she makes me. She’s been doing this for 4 months now. Today I sat in another seat so she couldn’t face me and grab at me and my stuff and she followed me. I get really bad anxiety when I can’t get space and I’m short( 4 feet 11 inches) and she’s almost 6 feet tall and I felt trapped. I had to leave the classroom so I just walked out. I saw her later in the day and she was mad at me bc she knows if the teacher had noticed I would’ve told him what she was doing and she would’ve gotten in trouble. I don’t know what to do, I feel bad bc she got bullied for her weight last year and she doesn’t have too many friends. I’ve tried a lot, saying no nicely and sternly, Id slap her but it only stops her for a little, Id show that I’m uncomfortable, Id get mad, id take her stuff too, But she doesn’t take me seriously. I don’t know what to do, leave suggestions in the comments please...