11! Holy smokes. Just my opinion - I think he's trying to assert himself and find his place. I think you need to show him who is in charge and that that behavior will not under any circumstances be tolerated. But you would need him in your home for that. I agree with counseling or seeing a doctor. There may be a reason for his behavior.
As for your mom. I'm sorry and no she is not right. You have a lot on your plate. You are alone while your husband is gone most of the time and not much support. I know as a single mom how hard it is. My kids test me all the time and I'm stuck with them.
My youngest started acting like I'm all that and then some and I just recently started getting firm with her. Before when I'd get mad and yell she'd just be like whatever. Finally I started just calmly saying this is the way it is and here are the consequences. It's bizarre because she's like ok, and chats away like nothings up and she's not in trouble and we are best friends. Freaks me out. lol