Constantly scared

Ever since I was little I've always been afraid to stay home alone. Now im a stay at home mom of three kids 5 and under. Im constantly feeling paranoid, constantly looking over my shoulder like someone is here. I hate going in the kitchen because its by the front door. Is anyone else like this? I don't watch scary shows or movies because obviously they scare me lol I just hate being alone. If someone else is here im perfectly fine. Nothing bad has ever happened to me so I have no idea why im always like this. We live in the country with pretty close neighbors and 4 dogs. I really don't have a reason to be scared but I still am. Any ideas how the hell I can get over this? I'm so sick of feeling like this.