In addition to everything recommended already, check out the book "The Gift of Fear" by Gavin de Becker. He is the leading expert on stalking and obsessive behavior in the US. I was a police officer for a few years, and I recommended that book to everyone who came in with any kind of stalking situation. The police and the courts can only help once certain parameters are met, but developing an understanding and means of protecting yourself is something you'll always have. It's a good book to read to start building those skills.