Firstly, I want to tell you I think you did a great job of explaining your experiences, with dosages and all.
There must be some misunderstanding?
I would write and tell him there must be some misunderstanding. I'd reiterate what I've said, maybe placing more emphasis on which things are not great.
I think this can be cleared up with kindness.
I am sorry he was not more attentive in the beginning. I do think he'll come through for you, once the error is addressed.

WC