I think that this is part of illness. Have you tried to challenge your beliefs? Are you getting treatment at the moment? You need to realize that nobody is stalking you. I had delusions before and know that they are nearly impossible to stop believing them but if I can do it, anyone can. They are 100% gone now and I am much happier. I would advise you to challenge your beliefs and maybe change your medication if the one you're on isn't working.