OMG!!!! It's so hard to be a parent these days. I don't know if I have a solution for you since my son's problems are little different. But, I do want you to know that every parent sooner or later will have issues with kids and will not know what to do.
You know when I was pregnant with my 2nd child, my mother was so shocked I was having another one. She kept telling how hard it would be and that I (only child) was more than enough for her and I was a good child. I had no idea what she was talking about until my kids became teenagers.
Teenagers think they know everything and they can handle everything. But, they can't. Have you considered counseling to show your son how to handle stress and pressure? Even school counselor might help for free. Maybe someone can show him how to talk to teachers when they are on him? I am pretty sure it won't work if you try to talk to him, but he might listen if someone else talks to him. Does he have older cousins? I know kids love to listen to older high school age kids. Maybe school can recommend someone.
I hope this works out for you. Good luck.
It maybe too late to go back and make a new start, but it's not too late to make a new ending.
I eat to live. I don't live to eat.