Hug, hug. Know a few kids like him

They all turn out great in college.

The issue is that they don't like high school activities - too simple, too boring for them. And they are forced to take all the required classes to graduate.  It is a torture to them.  Especially the college application process.

Let him be (so he feels that he has control of his life). 

Get a therapist - at least he can voice his feeling. 

If he don't feel like going to school, call to excuse him from school that day.  

Don't worry about the grades.  Most high school classes are not difficult, including APs.  If he feels like it, he can catch up easily.

Let him feel that you are always back him up, and he would get better.