We adopted a black lab 13 months ago, and it quickly became pretty territorial. Occasionally, she would growl at me and the fur on her back would bristle up when I would walk into a room or in the front door of the house. It was often in a guarding manner with my wife and daughter, similar to your dog, but never so severe that I feared she would attack me. Regardless, it was pretty miserable for me for a long time. I didn't want to get a dog in the first place, but I lost that debate, and then the dog we got didn't like me, and I didn't like it. The first ~6 months was seriously a pretty depressing period for me. Eventually, the dog came around a little bit. She will come near me now, but she still shies away at times if I reach out to pet her, and she will still randomly growl at me. I can only assume that she was abused by a male prior to her being taken in by the SPCA, from whom we adopted her. Hopefully a trainer can reshape your dog's behavior and establish a harmonious relationship between you and the dog. I know how unpleasant it is when that is not the case.