autism and anger

[mandco]

My ds is autistic and has always had anger issues but lately it seems to be getting worse and he seems to be angry all all the time. I do think a lot of it is stemming from school which is always an issue for us but they are currently prepping for sats so its constant testing - he can't cope with getting things wrong or losing and there have been a lot of changes to their usual routine which he finds stressful.

The slightest thing seems to set him off and he has violent destructive meltdowns where he lashes out kicking/punching/ swearing or he smashes things, throws things, slams doors
None of the usual things seem to be helping and I'm at a loss as to what else I can try to help him deal with how he feels in a more constructive way.

anger is one of the few emotions he can actually identify so he knows that is what he feels and I always do the I Know your angry because xyz happened and its ok to get angry but its not ok to kick punch ect because you're angry.