Just a bit of anecdotal experience for additional thought: I did the same for years, ignoring the signs, pushing through long hours, etc. and eventually developed idiopathic epilepsy. As it’s idiopathic, there’s no known direct cause (e.g. no head trauma, no tumors, etc.), but there’s a decent amount of evidence that supports at least a strong correlation between my lifestyle (lack of sleep, overwork, etc.) and the development of the disease. And of course lack of sleep is now one of my primary triggers, but that’s also fairly common amongst epileptics once the disease is ‘active’.

Best wishes GP.

Edit: point really being: it’s mild burnout until it’s not.