I have a funny story for you and I hope it makes you feel better.
My friend's son who is going to be 30 this January used to have several plugs; most people call them binky's. He would go around if one was out of place and say, " where's my plug". He was about four years old when he stopped; however, when one was missing and he couldn't find one, he would hold his breath turn blue and pass out. I believe my friend would just turn him over on his side and he would regain consciousness. She said that it scared her and she talked to the doctor and he told her what to do.
Just to let you know my oldest brother would do the same thing when he was a toddler to my mother. My mother said it was because my brother would refuse to wear a hat in the cold.
It's all about the power. My mother said that she remembers almost 60 years ago, when her mother would ask her to do something and because her mother wanted her to do something, she wouldn't do it.
It's beyond me why they don't. My son who is two is doing the same thing; however with out the breathing issue. I hope that He doesn't start it. If he has a tantrum, I just move away and let him throw it.
I also talk to him about his behaviors and hopefully, soon, he will be more helpful.