Tag to Carry On
Although he lived on for a few more decades and raised a son that he loved with every fiber of his being, Sam died in that barn too and never recovered, always yearning to join his brother in Heaven. He tried his best to hide it but Eileen - his best friend and the best co-parent he could ask for (their romantic connection fizzled in the aftermath of Dean's death, took too much energy to even contemplate, but he was on board with being a father the minute she told him about her pregnancy three weeks after his whole world came crashing down) - saw right through him and tried her best to support him.
He didn't feel whole again until the moment he slipped away and finally reunited with his brother. The gaping hole closed up quick and he was finally complete again, now that he had his other half back. "I love you," he whispered to his brother on that bridge.
Dean glanced at him and beamed. "Love you too, kiddo. Are you ready to meet up with the others now?"
"Of course I am."
And they made their way to the Impala together, everything just as it should be.