You know your child best, so whatever you decide will likely work out well.
However, as a teacher I'd like to offer the following tips to perhaps help him ease back into the school year should you decide to give his school one more try. Please note, I'm not suggesting this is the only option or the best option, but just some tips to help him if he goes back.
Do you know who his teacher is yet? Call him/her and set up an appointment to meet before the school year starts, just like a 'meet and greet'. Your son will have the opportunity to put a face with a name and get to know his teacher before the hustle and bustle of the first day's activities.
Call the school to see if you can take a tour. Granted, he's probably been attending this school before, but have your son point out his new classroom, his locker (if he has one), where he takes art/music/gym classes, etc. Ask him about his favorite subjects, what he is most excited about at school to get back to.
About the 'mean kids' - did your son ever mention who those children were? Is it a possibility to ask the principal if your son could be in a class where the 'mean boys/girls' aren't? Maybe even ask your son who his closest friends are and request that your son be placed in a class with one or two of his friends. You may need to explain to the principal your son's issues last year with anxiety and the other students. As an educator, it is my strong, strong opinion that our first and foremost duty to students is to make school a safe place (physically, emotionally, and socially) for EVERY student. Children cannot adequately learn without feeling 'safe' at school.
Not every child thrives in a traditional school setting, so he may well be better off home-schooled. Good luck to you and let us know how it goes! *hmmmm I must be the first teacher Lynn has ever heard say this!