The small self frequently experience exhaustion, in a variety of different ways and from different causes.
One is physical exhaustion. The other is mental exhaustion, typically from resisting experiences.
And yet, when we come to ourselves as space & awareness – as the Witness, the function of experiencing, the formless unborn – we find that this is distinct from any concept of exhaustion or not exhaustion. It does not apply. So we can find a place of rest here, especially as we recognize it as the context for our experiences, including that of exhaustion of the small self.
I am experiencing this today, as I had some food which drained my energy (sugar bomb) and possibly from being in a situation which is difficult for this small self (may have been some traces of resistance to experiences there).
When I shift my attention to the small self, I see exhaustion. When I shift attention to the context of these experiences, that concept does not apply. There is only space & awareness, untouched by any experience. Recognizing myself as the holarchy from one through to the other, I see one as the (boundless) context and the other as the (bounded, finite) content.
And this makes it OK, even something to appreciate.