High functioning autism + extreme anger

This is a long old story, so I'll keep it brief. I'm a single Mum of 3 lads, the youngest of whom has a diagnosis of ASD. There is no Learning Disability and he is in mainstream school. Performs well educationally, but has massive anger issues.

I'm a psychiatric nurse and I work with people with severe autism and challenging behaviour. Doesn't make it any easier to deal with, despite my knowledge and training.

I'm bloody knackered, sad at seeing my children upset... The eldest two are at their wits end and my youngest swings between rage and depression, fed up with things being broken all the time when my youngest has a huge rage...

Don't know what to do next....