Getting A Restraining Order Against My Abusive Stalking Parents

I am a 20 year old young adult living on my own with my partner, I am attending school and in recovery from some traumatic events that have affected my health, includeing homelessness and abuse both of which were perpetrated by my biological parents when I was 17-18. My bio-parents left for Mexico not long after my bio father physically assaulted me and I was told to "pack my shit and get out". I have expressed many times to them I do not wish to speak with or be in contact with them, however my bio-mother always finds a way to contact me. Be it mail or finding me in person. She showed up at my first class this semester waiting outside to give me a gaslighty "Christmas card". I have no proof of the assault aside from my testimony, and they could just turn it around on me as its 2v1. What should I do?