essbee, oh I just don't know what to say. So relieved to hear the head teacher is on your side.
I think it's much healthier of you to be angry about the help you are so not getting rather than blaming yourself. You know it's not you, don't you? Keep shouting at the professinals - hope real support comes out of the meeting.
From your latest descriptions of your son's behaviour, I have to say, IME this is so different to simple naughtyness. I am sure he has many lovely times and can obviusly cope with school, beavers etc but he really needs help, doesn't he?
Are you going to talk about your dd when you go to the meeting? if you say your son's effect on her is worrying you a lot, and she is in physical danger from him, would that speed up help? I don't know, but just wondering if this is something you could try.