I thought the ending was really good. At first I hated the ending because I was afraid of watching it so I read what happened. Then I went back and watched the ending and thought it fit perfectly with the story.
At the end of episode 15, with him in bed in the white room, his subconscious was giving him permission to rest. To release his pain. It's like he took a breath.
The amnesia allowed him to accept how he was. He hated himself in a way because of what everyone said about him. He didn't know who he was. He thought he was a bad person and couldn't accept the love coming from his wife. He felt he didn't deserve her love.
He didn't know how he'd change.
Now he has to accept who he is, forgive himself and figure out who he is. The amnesia allows him to be his true self. To never question his love and reasons for doing things. To finally understand himself. To stop hiding, stop running and to live.
He had to come to it himself. He couldn't accept people telling him who he is. He needed to accept himself and come to it on his own.
Which he did and is starting to.