Stimming and distressed

What age is he?

To help you need to focus on the root cause of the anxiety rather than the stimming behaviour itself.

I suspect something was making him extra anxious which led to the increased levels of being upset. Work out what that is and you have a good chance to deal with it and prevent a recurrance.

He’s seven. Thank you for your help 

He’s seven. Thank you for your help 

Thank you usually he’s stimms calm him but not last night 

The following books should give you a lot of background info as well as practical advice on how to idenfity, manage and prevent the anxiety build ups that are happening, but also what to do when they go from building up and into meltdown.

Managing Meltdowns and Tantrums on the Autism Spectrum - A Parent and Caregiver's Guide - Jenna Ward-Hawkes, Melissa Rodi (2019)
ISBN 9781785928406

Managing Meltdowns - Using the S.C.A.R.E.D. Calming Technique With Children and Adults with Autism - Deborah Lipsky, Will Richards (2009)
ISBN 9781843109082

You know him best so will ultimately be able to fine tune any approaches to the issue, but importantly you can teach him how to do it for himself when at school and eventually in life away from home one day.

Good luck and please come back for advice or even just chat when you want to.