This is good advice

The best action is to just go to bed at a reasonable time tonight, even if you’re not tired. Lie down, close your eyes and relax. Even if you are awake for longer than normal, you will fall asleep eventually.>

Quite a while ago I was listening to a pod about sleep (Ologies: Somnology. Highly recommend Ologies in general!) and they were saying that even if you don’t sleep at all simply lying down and resting is beneficial. It’s not as good as proper sleep but it’s a lot better than staying up.

I’m ADHD (no autism afaik), very late diagnosis (47). The very longest I’ve stayed, pre-diagnosis, was about 42 hours. I wasn’t studying at the time so not terrible but not great either lol I fairly regularly go over 24 hours because I do on-call shifts once or twice a fortnight. It’s not a great experience and not the healthiest thing to do really.