I am a single grandmother and have had guardianship for my grandson since he was 2 yrs old. He has always been somewhat resistant, but now that he is 16, he is verbally abusive and refuses to go by the rules. He is very angry and my like has become miserable.

I've tried counseling but he just manipulates. Sometimes I am afraid of him, he has a very bad temper. I can't seem to control him. He needs two parents so he cannot bully.

Are his parents in his life at all?

You are in such a tough spot with a defiant 16 year old. That you feel fearful is a terrible way to live.

You have been to counselling, and I gather there was no insight as to what is causing this behaviour? Is he in school? Do you suspect drug/alcohol use?

More information would be helpful.

Have you looked into military school or a bootcamp perhaps? So many kids lack discipline in today's society! Just a thought.

Where do you live? You might want to contact Social Services about foster care until he is 18. It's tough enough for many parents plural, and single parents, much less a non-parent trying to raise a teen alone.
How about Big Brother, or is he too old, or resistant to that?
If he knows you are at the end of your rope and looking into other situations, he might shape up. But not too likely... teens don't usually have a clue what's out there in the world.

He needs a strong male figure in his life right now. Do you have relatives or family to support you? How does he do in school?