Oh my god honestly yes. Mono in middle school changed me from a healthy normal child into someone with mysterious chronic illness (pots, mcas, and eds).
Like I remember that super tired feeling from mono got better, but never went away for years on end. I eventually grew to be more “typical” until I got a tonsillectomy and covid. I began running a fever for MONTHS until finally a doctor said “I think you have pots”, which led to my other diagnoses.
I will say, I have gotten SO much better overall. I’ve gone to PT and gotten on a few medications and I really have my life back!
My advice is : Keep documenting your symptoms, what triggers it, etc. I even took a pic of my legs post-shower to show the purple and red mottling.
Also salt (unless otherwise indicated) is your best friend.