You are not the only one tearing up. I wasn't quite sure whether to be sad or happy. One thing we learn from Supernatural is that Death is not the end and really, Sam couldn't have asked for anything better than to go on his own terms with his brother by his side. I do wish we could see Castiel's death though. I think that is the saddest part. Dean and Sam will always find each other, but Cas is alone. :(
I often wondered as I was reading how you could possibly end this without making everyone hate you, or even end it at all and this is the answer I never imagined. Well done!