You could try getting in touch with this breeder of Parrots etc. They might be able to steer you in the right direction....Sandford is not far from you.
http://www.milkwoodaviaries.com/exotic-birds.html
The OSPCA in Newmarket will take in surrendered birds, they are normally only there for a few days before they are adopted, but it sounds like your bird needs to see a Vet.
I, like Melinda am curious as to why your Cockatiel cannot sit on a perch
