I know it's not in the usual style of this board, but may I send you and your DS a virtual {{{{hug}}}}?
It's clear your DS has behaviour challenges, and that you know he does. But it doesn't sound as though either of you have any confidence in the school's ability or willingness to help, so it's hard to see how leaving him in this school next year is going to help.
I think in your place (to go to the title of the thread) I'd homeschool, with the idea that this was a one-year plan in the first instance. I'd use as much time as necessary over the summer and into the autumn for deschooling. I'd set up therapy for DS and some kind of group events/classes where he has a chance to practise being with other children under adult authority but with less stress than school. I'd hope that by Christmas everyone would be feeling better, and that DS would have rediscovered his confidence and enjoyment of learning, and would hold off making a decision about what to do in the following year until then, if at all possible.
