I hope you don't get so used to it's just your familiar look.
It's always easier said than done, but you need rest and sleep. It not effects what you do, it's a drag on the mood and pretty bad for our overall health and functioning.
Of course it could be medical or something else, but I'm surprised you haven't split in two as a necessity to keep up with everything.
Sometimes I get startled when someone tells me I look tired, because I don't even feel tired when they mention it... perhaps its sinking into the way I carry myself.
I've become a stickler for getting my sleep, though I sometimes get criticized for it. Some of that is the unconventional hours I keep, others I think is just the culture. "Why should she sleep when she could be getting up earlier and getting more done?"
I think my tests came back okay at my last check up. A little low on potassium they said, and overweight, but no major red flags.
I just don't get everything done. Don't like my unmopped floor or the extra dishes in the sink? Do 'em yourself. (Though people get critical towards that, too, but they can kiss my hindquarters.) But I sure do get pooped trying to get what I do get done...