Grim Wolf
Your animagus should be the Grim Wolf, a large black ghostly dog figure, often associated with death. Don't be worried though, this just means you'r adamant about what you want in life, and even if you're misunderstood you know and accept who you are and that's what counts. Grim have a reputation for haunting church yards, though this is actually a misunderstanding, as they are in reality guarding the lost souls there, just as you consider yourself to be fiercely loyal and protective of all your loved ones. The grim wolf animagus form would be perfect to your personality.
As the Weasley twins once said, and I quote, "Wicked!"