You are DEFINITELY not alone. My young boy is going through bullying as well. But one thing I will say is that our school district has been very good about dealing with it. We've had several meetings with the counselors / principal...actions have been taken to stop the bullying...and the counselor regularly checks in on my son to see how he is doing (thus making him feel better about going to school in the first place).
If you're school isn't handling it to your satisfaction, it might be time to raise the issue at a board meeting or district meeting (someone with higher authority then the school's principal). That might help get their attention.
Best of luck...and keep us posted how things turn out for you. :)