Understand that your personal safety is being threatened, so it would be wise to heighten your guard. This may include changing daily routines, arranging for a different place to stay, investing in additional security features for your home, and making it difficult for the perpetrator to contact you through every conceivable means. On your person, you can also arm yourself with self-defense articles like a pepper spray or stun gun.
Lastly, keep your friends and family informed. They may offer invaluable help in identifying your stalker. Ask them to inform you immediately if they spot the perpetrator trying to get close to you. They can work in coordination with the expert private investigator services you hire.