15 year old son recently diagnosed with ASD, at my wits end

It's been a long hard road, but after 3 years with CAMHS my son finally has a diagnosis. Part of the lengthy process has been because his careworkers kept changing but part of the reason is also because some of them couldn't understand why he seemed to cope with school i.e. his behaviour at school appeared 'normal'. Anyway, after all the assessments they have finally come to the realisation he does have ASD. This was communicated to us about a month ago but he has not yet been told. We would prefer his careworker or someone to tell him this so they can hopefully better communicate it than us.

Life at home is evermore difficult. He is totally obsessed with his 'devices'; Xbox and Ipad and very rarely leaves him room. I've had to put time limits on the wifi otherwise we would never be able to get him off them, but this causes issues. He shouts his sister when he knows it is about to disconnect him and tries to get her to extend it as she knows the password. If I go in and ask him to come off he swears at me, shouts, stamps his feet and if it disconnects, he'll throw his Ipad and throw his things all over the floor, sometimes this might be drinks and food he deliberately throws on the floor.

At the moment he is supposed to be revising for his school tests (he is coming to the end of year 10, and next year is GCSE's) but getting him to do any study is near impossible. He is quite clever but puts absolutely no effort in. I dread him doing his GCSE's next year as even though he is capable of doing well, with his current behaviours I don't think he will do any revision and if we turn off his Xbox/Wifi he will probably wreck the house. To make things worse he has said he want's to go to the Sixth Form my daughter to goes to and won't even look anywhere else, but at this rate I don't think he will get the grades he needs to get in.

When he has a 'meltdown' about coming off his devices he rips his clothes, to the point where they cannot be worn anymore. He has a football 'blog' on Instagram and does a post every night. I warn him how much time he has left to post his daily post, but if he knows it is about to go he starts shouting and then can be when he starts ripping his clothes, if we either remove his devices or access to the internet. Last night he totally ripped a pair of adidas shorts and an adidas top which are ruined. Last week he ruined to pairs of Calvin Klein boxer shorts, prior to that he has ripped school trousers, and other t-shirts. I'm at my wits end and don't know how to get him out of this cycle of behaviour !! It's impacting massively on the family, especially my daughter who is continually on edge.

Any advice would be greatly appreciated...