I won't be of much help because I don't know what you and your precious little boy are going through but it breaks my heart reading that
I may be jumping the gun here, but I say if he's going to end up being homeschool anyway and it's feasible than go ahead and pull him out.
Sorry I can't be of more help, I can only comment on what I would do if it were my child and me in your situation.
Have you talked to the teachers?