Stalker strikes again!!

Hey..im starting to worry about my life and well being. He keeps showing up at my job but he never tells me hes coming..WTF?? Monday he came a sat and watched me teach class for TWO HOURS!! Its hot in the pool when your not in the water..but he didn't seem to mind..he's crazy. I then he popped up yesterday..and i stay home today..and i hear he popped up again. I'm not sure what i did.or what i should do...