Masking is a real skill, and an exhausting one. Here is what I ask in the first hour, what I do about the constant checking, and what changes first at home.

Masking is a skill, and you built it well.
You watched how other people stood, how long they held a look, which jokes landed and when to laugh. You kept a running list of what to say and what to leave out. That is observation and pattern-reading, done with real effort by a child who needed to get through school.
It worked. It got you through work too, and now you are good at your job and people tell you that you are lovely. The cost is that it never switches off. You sit in the car outside your house for twenty minutes before you can go in, and by seven there is nothing left for your partner.
The first hour is mostly talking, and what I want first is the history of the mask: where you learned it, who you learned it from, and what happened on the days you got it wrong. Most people go back further than they expect, often to one playground or one comment from a teacher.
Then I ask what the checking sounds like on an ordinary day. People give me lines like "Did that sound sharp?" and "Am I looking at them for the right length of time?" It runs while they listen, while they talk and while they eat lunch.
I ask about the car. People are usually a little embarrassed by it. Most say they need the quiet, and that they replay the day's conversations, which becomes a second shift after the first.
The tiredness has a shape. Most people tell me the worst days are the ones with the most people in them, and that the first quiet weekend is spent doing very little. School holidays are often the first time in months they feel like themselves.
The mask took years to build and it works. The checking that runs underneath it all day is what uses you up.
Something I have stopped being surprised by: people arrive expecting me to take the mask away. I do not want to. You need it in some rooms, and it is yours.
There are two layers, and I work on them differently. The first is where the lesson was learned. Where there is a specific memory, such as being laughed at or told you were too much, I use EMDR.
EMDR is a method where you hold the memory in mind while following my hand from side to side with your eyes. The memory is reprocessed, so it stops firing as though it were happening now.
Before any of that I spend time on preparation. You learn a way to settle yourself and a place in your mind to return to, so you can always step back out of a memory.
The second layer is the checking itself, and clinical hypnotherapy does most of that work. You are relaxed and focused, and I talk you through the scan as you describe it, in your own words. I change what it treats as needing attention, and I give it an off position, which it has never had.
I do this part slowly. The checking was put there to keep you safe, so I leave it running for the rooms where you want it and change what it does at home and in the car.
Between sessions I ask you to notice one thing: the moment you put the mask on. Most people have never caught it because it happens too fast.
The car is usually first. Ten minutes instead of twenty, then five, and the drive home stops being a replay of the day.
The first thing to shorten is usually the time in the car, and the replaying of the day gets quieter.
Sleep tends to follow. Once the day stops being replayed, people say the evenings feel longer and the weekends stop being spent recovering.
After that comes the choice. People tell me they notice themselves putting the mask on at the school gate, and that they can take it off in the staff room when the moment is right. The mask becomes something you choose to put on.
I do not remove autism, and I would not want to. What changes is the monitoring, the exhaustion and the time it takes you to recover.
By seven in the evening there is more left, and that is usually where the people close to you notice first.