Are you worried because something happened in a bathroom stall before? What I do when I have that sort of anxiety is decide in advance what to do if the thing I worry about happens.

Lately, I was stalked by a guy that someone else said had attacked and raped them in the past. So I carried something I could use as a weapon when going places where he might turn up. I carried a big shovel to check the mailbox and it made me feel better to imagine myself whacking him with the shovel if he was waiting outside my house to get me.

I know its not practical to carry a shovel in public, but is pepper spray a possibility? Or bear spray (super strong pepper spray for bear attacks). You could have it ready whenever you go to a public bathroom. It might be a good idea to put a big sticker on the bottle to make it easy to tell if the spray is pointed away from you because it's easy to get aerosol sprays the wrong way around.

Or you could carry a wrench in a big purse, I sometimes carry that instead of a shovel.