There are too many simpler explanations than a lot of the ones proposed…. like the POTS (Exhaustion / fatigue is listed as a symptom) a stimulant could potentially increase the tachycardia, the severity of the depression, and the side effects of the non-stimulant meds.
I would want a comprehensive overview of everything that you are dealing with for an explanation with an updated physical and blood work-up.
After that, I would push for a second opinion.
This is definitely not the work dor Dr. Google.