Shutter Island

So i watched the movie with “the biggest plot twist” which i find very nice but if he was really a delusional man how come they faked the ferry scene like where were they coming from i want more of the backstory but anyway the movies end for me is that he knows is still a lie that’s why he wanted to go there to lobotomy and end them😭 i think myself im starting to be delusional, i truly believe his a marshal