If this medication has worked the best and if the therapist you see biweekly recommends increasing its dosage to make it even more effective, why are you resisting this adjustment?

It seems logical, if you find a pharmaceutical agent that works, to look for the sweet spot where it is most useful. That would require going up and down on the dosages until you hit the sweet spot. Why are you not experimenting with that? You seem to be sabotaging your own treatment, not being a good partner in your own healthcare.