My first two questions would be how long have you had the bird, and second, how long was the bird at the Rescue?
If the bird was in the Resuce for a while, contact them and see what they were feeding and go back to that until you can transition the bird over slowly to other foods.
I feed Roudybush and Mazuri (fed in zoos). They get fresh veggies (except avacado & onions) daily. I sprout for them also (sproutpeople.com)They get fresh fruit daily also. In the evening, they get frozen mixed veggies and brown rice for dinner most of the time, but there are spaghetti dinners or pizza on occassion.
Basically the birds get whatever I eat including chicken and eggs. The only foods I do not feed are avacado, onion and caffine (all very bad)
They get: broccoli brussel sprouts sweet potatoes green beans, zuchinni, yellow squash, celery, radishes, peppers, green & red & yellow peppers, grapes, banana, apple, pear, orange. They love fresh corn on the cob!
Also, I would recommend you find an avian vet to care for your bird. It sounds like your vet has put him on Monkey Chow (Parrot Chow) To locate a vet in your area, go to www.birdsnway.com/birds/vets.htm
I believe I noticed that you posted from NJ. There is a bird club called South Jersey Bird Club. Their web page is : http://www.angelfire.com/nj3/sjbc/
Good luck and keep us posted.