Is it an age thing or something else?

Helloo everyone, I just wanted to see if other people have had the same thing if so what helped if anything ? So my child has always been challenging and I’ve always found ways of managing it, he is 4. Recently he has gotten so much worse. He’s screaming and shouting all day (not an exaggeration) we’ve even had to go to our neighbours to apologise. He punches, slaps, kicks, headbutts himself and us but also pulls his hair when frustrated and can go from 0-1000 in seconds. I’ve spoken to soo many professionals that tell me it’s just his age …… is it?? I feel like I’m at a dead end. We have boundaries that haven’t changed his routine is the same nothing in his/our life has changed. So I can’t blame that. I’ve tried everything that I’ve been told to do to calm him down and nothing works for example 🔴 Distracting him, giving him cuddles, giving him space (he follows me). Giving him options, taking privileges away, put him in his room to calm down ( he destroys his room) Nothing works. I’ve even tried to get him looked at for ASD/ADHD and he’s been refused. If anyone has any helpful advice It would be deeply appreciated ❤️