Hello...I'm Dr. Coldiron and I will attempt to help you with your veterinary question!
Your bird definitely has a serious issue going on. Birds tend to hide any illness until they are very ill. Ataxia (incoordination) in birds can be due to a variety of issues. Some of the more common issues include: bacterial infection, viral infection, neurological issues, heavy metal toxicity, fungal infections, endocrine disorders, and others. I don't think there is much I can help you with over the internet. You need to get your bird to an avian vet and have him examined and some tests run to figure out what is going on and address the issue rather than treat symptoms. Blood work would be my initial step and based on the outcome of it, I would pursue other tests. The initial blood work can lead the veterinarian in a specific direction hopefully...such as an elevated white blood cell count indicating infection. I could go on and on about different causes for the behavior your bird is exhibiting, but it will not fix it! You most definitely need to have him checked out!
Don't worry about accepting this response, just get your bird to his vet ASAP!