abby, what you describe could be due to a number of things, and he really needs to see a psychiatrist to be properly diagnosed. If he gets professional help, then he could get treatment that would help him feel better.

I know this must be very scary for you. The best thing you can do for your brother is try to convince your parents to take him to a psychiatrist. Only a doctor can really diagnose what is wrong, and provide the treatment he needs.

Good luck.
*hugs*
mj