I agree with Heather. I would use another Avian Vet.
Also I think fingers crossed, praying and taking notes aren't going to do it IMO & IME.
I would rather have heard ya say that you are going right out to purchase that heat source (without light) and mount next to the perch or area where he sleeps. Leave on a small 7watt night lite also for him to see where the food & water is.
I would also have rather heard ya say you will immediately give him that food I mentioned and some calcium supplement too.
Did ya feel the chest bone to see if he is maintaining weight or losing it?
Just trying to help the bird, not scold ya. 8)
Btw, I suggest not to buy seed in a local pet shop that houses birds as many diseases are air-borne and travel throughout the shop in/on feather dander and dust in the air from decaying food and feces etc.....Some of that airborne stuff can land in the bulk food bins that the shop owner scoops the food by the pound out of. I would only buy food, from a pet shop housing birds, in bags that have not been ever opened etc......JMHO.