Hi strophy, I have a very similar story to you. Like you, I am physically very healthy but I have this horrible persistent mental fatigue that never goes away

I always have low energy and I sometimes feel as if I am in a dream like state.
My mental fatigue started suddenly 2 years ago after taking a single dose of diflucan (fluconazole) for thrush. My only other symptom is I bloat after everything I eat or drink! So I’ll wake up with a flat stomach but by the end of the day I look highly pregnant!
I've had every test done (for both the fatigue + bloating issue) but all results have come back negative

I used to think I had CFS (mainly because of the sudden onset) but I am 100% physically healthy (I run, ski, go to the gym regularly etc.). Could anyone shed some light on what this could be? Have you found any answers strophy?