DS is 13yo and is autistic, part of his particular profile involves difficulties with emotional literacy and emotional regulation. Usually he is a happy, bouncy, affectionate kid and genuinely a joy to be around, you can't be next to DS in a good mood and not end up in a good mood yourself. He does have areas of day-to-day life that are tricky for him, there are ups and downs, he has meltdowns here and there but overall we scaffold him as best we can and he's progressing.
Over the last couple of months he's gradually gotten moodier and angrier until he's now at the point where the slightest thing sets his temper off, it's like he's on the cusp of a meltdown most of the time. He calls his siblings names, throws stuff, is verbally aggressive, storms off, and when he's not storming off he goes on a sit-in protest (basically sits/lies down and refuses to budge. He's grounded all weekend and has no phone or gaming time after telling his dad to "fuck off" after his dad told him to stop shouting at his brother (DS was singing a song, his brother joined in, DS screamed at him to "shut the hell up"). He does not get spoken to like that by us and we do not swear at/around him before anyone jumps on that. He's also being really controlling around things like food, his routine, clothing, etc. He's usually very particular around these things anyway as part of him being autistic but it's like they've escalated, all of his traits seem to have escalated too. It's like he's always in a disregulated state.
This behaviour is not like him and is completely out of character. From speaking with him while he's calm he knows its wrong and he doesn't want to do it but he doesn't understand why he is doing it or how to stop once he starts. He says he's not being bullied but he does say he doesn't like school because he feels stupid and that he hates himself so it's making him angry.
We're using zones of regulation, we have signals agreed with him that he can give where he's not coping so we can step in, we're watching for his non-verbal cues that he's starting to get aggravated so we can intervene as needed, we're taking through our feelings (narrating them), we've gotten Mighty Moe back out, praising positive behaviours, etc etc and doing all the things we usually do as well as looking for ways of adapting his emotional/mental toolkit to support him through this. He knows he can speak to us about anything and that if he's not comfortable he has ither trusted adults he can talk to. I've made a referral to the school health team to see if they can offer any support too and if they can go into school to assess exactly what is going on there and see if there are any areas he's finding especially difficult (he does have emotional support written into his EHCP but the last reports for it were done nearly three years ago). He had a paediatric development check-up last year and they told us he was showing signs of puberty and that a lot of autistic people find this stage difficult as it can be such a roller coaster.
Is there anything anyone could suggest in the meantime that we maybe haven't considered or any books, etc that could be useful? Particularly parents of autistic teens or autistic adults who have gone through this themselves, I'm posting here rather than the SN boards for the traffic.