Burnout and active rest

Q: how do you stop doing too much, when the way you self-regulated is by being active?

There's a sweet spot somewhere, but probably a lot of trial and error required to find it.

I think I need recovery from activity, rather than pre-emptive charging. My brain needs stimulation - sitting still and having nothing to do is not an option, because my brain is wired to constantly be looking for activity. 

So how do I work out what's too much, and what's not enough? And how do I get past the guilt I feel once I've burnt out?