Looking for some advice with what I think might be PDA

So my 7.5 is not diagnosed but I'm very certain he is autistic and possibly ADHD. I'm also pretty sure I am too. Unfortunately can't get doctors to take me seriously at all.

Anyway, this week my son had the dentist and we found that he has some pretty bad tooth decay. He's going to have to have a couple of teeth removed and needs fillings in others. All baby teeth so that's a saving grace.

I am absolutely devastated that it's gotten to that point - last year the dentist said they looked fine but he didn't do x-rays. This year he said they looked fine but then did do x-rays and... Yeah not good at all.

Obviously that means that proper tooth brushing is not optional anymore. Not that it ever was optional but I feel we've been too permissive/avoidant of his meltdowns around any demands.

Some days he will outright refuse, some days insists on doing it himself (fine but not ideal). Most often is that bedtime is so horrendous that the thought of putting an additional demand on him to brush them just goes out the window.

Same thing with mornings really.

He does seem to accept that he hasn't got a choice but omg it's basically impossible to brush his back teeth properly because he puts his tongue in the way. I showed him in the mirror exactly what I needed him to do. I got him to practice it and he absolutely can move his tongue out the way. As soon as the tooth brush is near his tooth, he moves his tongue. I ask/tell him to move his tongue out the way and he growls/grunts at me and just will not do it.

Then I try to explain again and he starts yelling over the top of me so he can't hear what I'm saying. Which in turn burns through the little patience I have and I end up yelling at him to stop yelling over me (ironic I know).

It's not just tooth brushing either, he does the yelling over thing with pretty much anything he doesn't want to do. And I try really hard to only ask/tell him to do the necessary things.

Help please 🫠