The information you have already been given here is an excellent place to start. Also, when you take your bird to the vet talk to him about your bird's violent tendencies. Often avian vets have literature they will give you at no charge, or beable to recommend other avenues of information on this matter of aggression. There is a host of causes for your birds problems, medical, abuse, neglect, the list goes on. Each shall have to eliminated which will take time. Don't give up, this is the most superior site for information to be sure. USE the search and read, read, read.

Though I agree the punctuation could have been better. However, I only saw it as a minor thing compared to the concerns and love you obviously have for this bird. I personally apologize that the comments in regard to pure grammatical errors in your post were put first rather than effort placed in order to point you in the right direction. YOU are not stupid so don't degrade yourself by saying such. Someone in your bird's past was the stupid one! In fact you obviously have the intelligence to search for help and then post your questions. Kudos to you and your love of animals!