My 9yo is very much the same. He's probably dealing with multiple anxiety issues, and other things as well (see my recent posts for the painful story). You're definitely not alone.
Getting through these issues can be hard. Finding a good therapist may be helpful.
My sons also thinks everyone at school hates him or "thinks he's an idiot" if he gets teased even a little. Unfortunately, teachers don't see all the teasing and it is very hard for us to deal with. The emotional outbursts make him even more of a target.
Please let us know how you're doing. Good luck.
