Throwing yourself into the fire won’t smother it out unfortunately.

Make sure she isn’t allowed on campus. I can’t imagine she would be after what she pulled. No campus would want a raving loon back on the premises, but make doubley sure with campus security.

Run some scenarios with you GF if she ever approaches you in public again. You both find a safe spot (or she can safely flee, but you need to be somewhere she can’t physically reach you) you can lock yourself in and call the authorities. Start really taking in the surroundings of the places you frequent so you know your exists and safe places.

Sounds like the beginnings of stalking and attempts to isolate you by the theatrics alone. Don’t give her an inch.