OMG that hurt! It was perfect, but it hurt! It makes so much sense, but OMG it HURT!
Honestly, as much as I ADORE Rumple, and have done so since the very first moment I saw him, and as much as I want Rumbelle to have their happy ending, the way your fanfic played out, it would have been so true to character for Rumple, and that death would make sense.
It would fit with his acceptance in 311 that his son could have a happy ending, just not with him.
It would fit with his acceptance of responsibility that he had in 311.