about 2 and 1/2 weeks ago i adopted a pionus blue headed parrot. he seemed nice. hes 4 years old. I took him to the vet for a check up and they said he had an upper respiratory infection so now hes on meds. they tested his poop and his bacteria is 100% bad so hes on meds for that to and will go back to the vet when he finishes his meds. he has bonded to me quickly but when he gets stressed when the dogs bark he bites me (this has only happened in the first week and he was very stressed. when my brother walks in my room marty will puff up and hide behind his cage. when my grandma was moving something in my room he crawled off of his cage and chased her trying to bite her feet. my mom came in my room and he flew at her and bit her ear. he has also flown at a family friend trying to bite them. he is very aggressive he tries to bite people all the time and everyone is to the point of being very afraid of him. i dont know what to do to make him better because if someone else even tried to pet him im sure hed bite them. please give me some advice on how to tame him and socialize him.