0 I'm scared

Have been under a whole heap of hurting pressure recently.
My Dad's health is failing, I need new specs cos my eyesight has gone south even further but it's the Aspie teen that this post is about.
Only silver lining was tonight's successful GFDF conversion of this self-saucing chocolate pudding here - I substituted the milk for fruit juice, flour for Healtheries GF baking mix and the butter for oil.
Yeah, I got all a'quiver over chocolate *snort*.
Aspie teen has not been 'quite himself' since his major meltdown of several weeks ago; his mind is not engaged, his focus is off-kilter and it's like all the autistic traits have become magnified.
His impulse control is broken, his meds don't seem to be clicking in and conversations are running off into different tangents.
We've finally got in to see a medical professional to get an assessment started, thank the flipping Goddess on high, but it's like the kid's been holding onto the last shreds of control and now that he's started seeing someone he's relaxing the grip on those reins.
Which scares me beyond silly.
I'm sitting here putting on a 'normal' face for hubby and my Dad so they don't freak, to the teenager babbling nonsense (who was studying at uni only 2 weeks ago) I show the 'normal, calm mummy' face so he doesn't freak out, either.
Cos he's all on the defensive when I even casually ask him anything about his thoughts, his behaviours, his driving urges, etc.
What do you say to a teen who has forgotten they've literally-not-2-seconds-earlier just got off a bus at a bus stop only to turn around, look at the bus stop sign and complain that "We've walked past the bus stop how are we going to catch a bus, now?"
Then almost 2 mins later, after the explanation, again ask "But, where are we going to catch a bus from?"
This shit scares me.