Shutter Island; What happens in the end!

Martin Scorsesee chose to make both insanity and sanity a possibility resulting in exactly what is going on on the movie.
The movie is really exciting. Till the end i didn't know whats happening.We don't know what happens at the end.

When he says, “what do you think is worse, living as a monster or dying a good man?”, I think that means that he has the choice to believe what they are telling him, and live thinking that he was a monster who killed his own wife. Or dying as a good man in the sense that he rejects what they are saying to him, and sticks to the fact that he was a good husband and “died” trying to blow the lid off Shutter Island. But then again Scorsece did an unbelievable job really leaving the opinion up the to audience.