I have had two episodes of what I call "mitochondrial collapse". The first was in late 2019 and was probably an early case of COVID. I had severe respiratory issues and thought I was dying. started taking 1200mg NAC every 2-3 hours... I didn't die.
Did the same recently when I had an overwhelming fatigue and could barely get out of bed.
I suspect that 2-73 would be even better than NAC.
From the AI generated by a search for "fluoroquinolones mitochondrial toxicity"