You're in charge of his life. And your own life.
If his life is chaotic and jam packed, change your lives. This is the first thing to do when you suspect autism and ADHHD any way as so much environmental stuff can cause issues and when they go away - the symptoms go away.
I have an ADHD diagnosis. and an Autism diagnosis. My son has Autism and suspected ADHD.
It on YOU to change his environment and habits to one that is less hectic and hassled.
Get rid of the TV. Put your own phone in a locked box when you get home. Don't put him in extra clubs. Walk to school. Leave 20m earlier. Get enough, deep, uninterrupted sleep. Remove as many over processed foods, dairy as you can. Simplify your home environment, less furniture, toys, everything. Pare it all back
Spend Saturdays doing a 10 mile walk cross the countryside without a single device, just walking.
Don't take him to the supermarket - why on earth would anyone do that - get it delivered. Never walk past the shiny shelf of plastic crap ever again.
Don't take him places with a gift shop. My son used to epically melt down EVERY TIME because he could not decide what to buy with his own money he had. He would get stuck in the decision making and perceived pressure. Just don't go they are just money making machines anyway.
You have control over more things in his life to day than you will next year. Each year, you get less and less feedback and control and the school get more, as will your son.
Take firm appropriate action now.