Is this pda?

[PinkDaydreams]

Morning all!
I have a 4 yo ds, diagnosed autistic.
Lately his behaviour has been rather challenging, mainly around self care- hair washing, suncream application and teeth brushing.
I seem to have tackled teeth brushing in the evening, I do it whilst he is in the bath. He does have supper after this but to be honest I don't want to hype him up before he goes to sleep, so I just think at least they've been cleaned. The morning is a different story. He's chosen his own tooth brush and I've bought him new paste (no taste and doesn't foam), but every morning it's the same.....kicking me, biting, lashing out, screaming, slamming doors, throwing self on floor. It's such an extreme reaction. He won't have a bath in the morning, I've tried showering him which used to work but now he can't handle the feel of the water on his skin from the shower head. It also doesn't help that he doesn't like getting wet.
He is on the waiting list for ot, has been on it since December, and whilst waiting I have attended a couple of sensory processing courses and tried some of the strategies given.
I have read a small amount and heard of pda, is this an example of it?
I just don't know what to do, I love my boy so much and really feel for him when he's so distressed. I know he can't help the lashing out and he will always say "sorry for kicking you mummy" once he's eventually calmed down.
Sorry to waffle!

[PinkDaydreams]

Bump!

His reaction to hair washing is also the same, I seem to have tried everything but still he screams, tries to escape out of the bath, will cling onto me and try to climb up me to get away from having his hair washed and rinsed, fast uncontrolled breathing.

I should have also mentioned his anxiety. I've noticed more so lately, things like if his dad walks a few steps ahead of him, he full on panics and starts screaming histerically. Obviously dad now walks by the side of him with us. There's been a few occasions when we have run for the bus and it's driven off, whilst we've been running again his reaction is so extreme. Today I went out into the back garden to get the washing off the line and he thought I'd gone, he could see me though and I'd told him what I was doing. "Where are you going, where are you going...." sobbing uncontrollably, standing watching me.

Sorry to go on and on. I'm just unsure if this is pda and what help as a family we can give him.

Thank you!