I have hit a wall today.
I'm in hospital with my DS1 (9) (regular thing) DP is at home with DS2 (7) and DS3 (16 months)
We've had a problem for a while with DS2's anger, he has real violent outbursts over anything and they go on and on until he yells himself out of it.
They've gone from being "stupid idiot I hate you" to full destruction of the upstairs, throwing anything he can find down the stairs and making threats to cut us and kill us when we're asleep 

Firstly I don't know where he is getting these things from, I am really strict with the television he watches and games he plays and he certainly wouldn't hear things like that at home from us.
There are multiple things going on, sorry if this post goes on forever.
He is being bullied, he has been since reception, I have Ben in to the school hundreds of times,but as soon as things ease up we go right back to square one, this has resulted in it I'm stammering badly and his confidence is gone. The schools last response was the head telling me to be patient for a little bit longer as changes are being made, she couldn't say what.
He says he is jealous of his brothers, I Dan understand this, DS1 has a long term health condition that means hours of daily medical routine and his baby brother is just that, a baby, he obviously needs a bit more hands on attention. I have made sure thought that DS2 gets one on one time and has special things that are just his but it's not made a hot of difference.
The school have suggested asking for a CHAMS referral from the GP which I have done but have been warned that it's several months wait for an appointment and even then there isn't a lot they can do.
I have completely run out of ideas, I have tried star charts, love bombing, strict isolation for violence but nothing works, it's getting worse if anything.
I'm terrified he is going to either hurt himself badly or hurt one of his brothers so DP and I are currently taking daily beatings from him trying to diffuse him away from the rest of them.
He goes to his and DS1's Dads house every weekend, he doesn't behave like this there, he does to behave like it at school and he also goes out with a community support team and he is good as gold there.
He gets loads of time outside, playing and running off steam and he does weekly sports clubs and he eats well.
I've just had a call from DP to say that he's again torn apart his room, I can hear him in the background screaming abuse at DP.
What on earth do we do next? 