Welcome! You've come to the right place, and if you browse the forum you'll find that there are many of us here who've been where you are. Don't panic! For now, don't expect to find a group academic setting that will teach your son; you are almost certainly better off finding a very flexible preschool that will let him play, create, read, as he wishes, while spending time in a group with other children. Unless he's very unusual socially and emotionally as well as academically, putting him with children learning what he needs to learn now, at just turned 3, is unlikely to work even if you could find somewhere that would do it.
Do you have a good children's library nearby, and is your DS's reading good enough already that he can teach himself by reading non-fiction books? That was a lifesaver for us. That and google!
