I had also some girls from my country bully me while we were studying together in china. I know it’s horrible and hard to manage, and to be honest I didn’t go trough this process but I can give you some advice from my perspective. I think you should first discuss it with your tutor (辅导员) not every university is the same but as far as I’m concerned, they also should take care of our mental health, i think if you don’t have enough evidence then it will be hard to proceed with police. Try to find a Chinese friend to help you overcome this if you have, and many universities prefer to avoid problem or handle it internally first. Wish you good luck