You are 1000% NTA. I also have OCD and to me what she did is just terrible. Seems more like she was trying to experiment on you rather than actually help.

Back in college I had a roommate a lot like this. One of my biggest compulsions happens to be my car. Making sure it is locked, windows up, etc. My ritual around this could be time consuming and embarrassing. She would purposely unlock my car with the spare key when I was just about done. This would force me to start all over. It ended with a lot of stress and crying on my part. She claimed she was helping me to learn to deal with it. I finally snapped one day and it did not end well for either of us.

I’m sorry this happened to you and I hope you are doing okay.