Ohh dear - that's just awful! 
It does sound neurological from what you have described - BUT, you really need for him to be seen again.
Where abouts are you? Maybe we could help you with a RECOMMENDED Avian Vet. For example, the one my birds go to, is a Professor who teaches Avian medicine at our local University and I SWEAR by him!
I live in Qld, Australia - but there are people from all over the world here who could help you and your Aussie bird!
It does sound neurological from what you have described - BUT, you really need for him to be seen again.
Where abouts are you? Maybe we could help you with a RECOMMENDED Avian Vet. For example, the one my birds go to, is a Professor who teaches Avian medicine at our local University and I SWEAR by him!
I live in Qld, Australia - but there are people from all over the world here who could help you and your Aussie bird!