IMHO I would document everything AND send her an email explaining your boundaries again and how she is violating them. I'd save all texts you get from her, especially if they are weird in any way. If she is stupid enough to respond to the email save it. Speaking from experience you want as much confirmation and evidence as possible if you ever need it.

You could also play the overreaction game with her. You said that she has fallen to the ground in despair when you have tried to separate from her. So she touches you scream NO!! Start to cry. Make a BUTT of yourself and draw attention. And then as you continue to sob explain tearfully that you no longer can stand to be touched. If you draw enough negative attention to her when she misbehaves she might stop. Or at least move on to her next target. Good luck to you. Very sorry you have to put up with this at work.