I'm diagnosed autistic level 1, with an elementary-aged son who's very similar. It took me way too long to realize the following issue.
Essentially, for a while I wasn't fully recognizing just how much trouble I was having because of my own difficulties with transitions. It relates strongly to going really deep on certain tasks that I like to engage in. My son would start playing a bit, I'd naturally drift towards something else I found interesting, and then would get inevitably more dysregulated when my son suddenly needed my attention.
It sounds sort of obvious when reading this, but I think it went more unnoticed initially because any one interruption wasn't necessarily enough to cause me immediately large issues. But, kids have the tendency to demand attention a lot of course, and unexpectedly so. This all kept adding up. Combine that with all the yelling, running around, climbing all over me, etc. until it would push me towards my own shutdown or meltdown.
One thing I do to try to help (aside from getting more support from others) is to do tasks that are more repetitive or have chunks that can be completed in like 30 seconds before repeating. Things like sorting, organizing, light tidying, that kind of thing.
Still, it's somewhat annoying because I find myself wanting to drift back towards tasks I find even more meaningful, but are quite painful to have interrupted.
I was wondering if anyone else has this kind of experience too, and has figured out other ways to deal with it?