He can't blame you, you were helpless, you were weak. Simon knew you weren't fit to take care of yourself, he knew that no one could do the job better than him. You were the sole reason why he had abandoned everything he thought he was worth, he figured nothing could fulfill him with purpose the way you do.

Now that he has you, and now that he has all the time in world to prioritize you, there was no reason to doubt that you weren't special. You are the single thing that's keeping him sane.