Manipulation is a pernicious word, there is a lot of psychiatric literature on the misuse of the word, particularly by professionals.
As you said, he is probably transferring his distress and ambivalence on you, because you are his mother. He is 16, most of us adults have a hard time feeling and accepting our emotions, how do we know how to communicate them clearly if we don't know what they are in the first place? By learning to accept your feelings and to express them clearly without judging them, you can help him understand and accept his own. We are our children's mirror> sometimes the mirror gets foggy or dirty (metaphor)> so we clean it up, and continue...
Best to you