Well, stalking is usually just stalking, but yes, it is definitely a form of harassment. If you feel threatened for your safety, it is also assault. I know most people confuse assault and battery, but assault is when someone puts you in reasonable fear of an impending battery. Battery is when you are physically touched or harmed by someone, but there must be physical contact for battery to occur. Otherwise, it is just assault. Therefore, you could potentially press charges on this person for stalking, harassment, and assault.
I agree that reporting it to the police is the best and only option. They will probably advise you to get a restraining order as well. In the meantime, it is best to be wary and vigilant, and never go anywhere by yourself, stay out late, or linger in secluded areas until the issue is resolved, but even then you should always be aware of your surroundings and avoid dangerous hours and places. Good luck!