Me and my boyfriend got a new pitbull and she is about a year old. When we first got her about a week or so ago she was sweet and loving and only bit in a playful or accidental manner. She was only aggressive when being played with. My boyfriends parents made us chain her up so she wouldnt get hit by a car while we werent home or so she wouldnt mess anything up. Ever since then, we cant even pet her without her attacking our forearms and hands or jumping on us. We thought maybe she wanted freedom so we hooked her up to her leash and tried to walk her but she only bit the leash and tried to yank it out of my hands. She has not been abused at all, she has not been neglected, (we tried to get her off the chain as much as possible) but we cant anymore because shes so mean now. What should we do?