I think ASD and OCD is SN - you're v welcome!
My son has autism and he also hates change. Something that really helps him is social stories. These are things that set out the change and how to possibly respond.
Here's a sort of (not great) example:
We are going on holiday. We will drive in the car to our holiday house which will be different from our normal house.
The house
? I will share a bedroom with Mummy.
? I must not touch switches and buttons without asking a grown up or it could be very dangerous.
Sometimes,I will be allowed to watch TV in the house.Other times,I can read or play.I will try not to fiddle with equipment in the house.
Mealtimes
? Sometimes we will eat at the house.
? Sometimes we will eat at the beach.
? Sometimes we will eat at restaurants.
? Mealtimes should be a nice time for everybody so I will try to behave well so that everybody can enjoy themselves.
? I will stay at the table as much as I can. I will try to only get up if I need the toilet.
? I will try food that is given to me and not make a fuss if I don?t like it. I will just be polite and say ?no more, thanks.?
Bedtimes
? At bedtime, I will have a bath and a story, just like I do at home.
? I will then read for a bit, just like I do at home.
? I will then go to sleep, just like I do at home.
Travelling
? The roads are different on holiday. Some have no pavements.
? I will have to be extra safe on and near roads.
? This means that I must ALWAYS hold a hand near roads.
? If I get cross, I must say that I am cross and I must keep holding hands. I must be safe.
? I will carry my own bag if I am asked to.
Going to the beach
? I need to go to the toilet before I go to the beach as the toilets are a long long way away!
? It will be fun playing and swimming.
? I also need to be very safe.
? I must stay near one of my family all the time to keep me safe so I don?t get lost.
? I can play or I can sit and read. Sometimes other people will play with me.
? I must wear sun cream so that my skin does not get burnt (though it will go a lovely brown colour in the sun ? gorgeous!).
? I must have lots and lots of fun!
Feelings.
? It is OK to feel cross or sad.
? Everybody feels cross and sad. Our family might shout or be upset sometimes on holiday.
? I might feel cross or sad. I might want to shout or run away.
? I will try to tell Mummy or another grown up in our family what I am cross or sad about before it makes me turn into Cross J!
? If I want to go and lie on my bed and be sad, that is OK. If I am out of the house, I can move away from my family and sit on my own. But I MUST stay so that my family can see me.
I WILL HAVE KIND WORDS AND BEHAVE KINDLY AND SAFELY.
I WILL TRY TO MAKE SURE THAT EVERYONE HAS FUN.
I WILL HAVE A LOVELY HOLIDAY!
That's actually not a traditional social story - they're usually quite short and focused - but it's the only one on my computer!
Anyway, I'd do something like that, with pictures if necessary and maybe a worry/question page on the back for him to write down anything he wants to discuss or is unsure of.
J finds writing easier to process than verbal stuff and needs all the change laid out in minute detail.