My fun loving dog has suddenly shapped .?

I have a 1 year old male lab/ shar pei mix. He is not neutered/spayed. He has always been a very aggressive dog, but when it comes to my immediate family he is very loving, affectionate and protective. He does not like strangers at all. My dog has snapped at me occasionally or growled at me, but only very rarely when he doesn't like what I tell him to do, but never to the other members of my immediate family.Over the course of the summer I have noticed that he is becoming very disobedient, he no longer listens to me, and he is constantly testing me , by trying to snap back at me a lot. Today my dog was sleep on the floor and I was doing my mom's hair when all of a sudden "Smokey" that is my dog woke up, turned to my mom and started to growl at her with this low growl. The same growl he uses when there is a stranger around. He approached my mom, steadily growling and baring his teeth as if to bite her. I had to grab him and even then he tried to get at her. Should I get rid of him?