Our Shattered Past (слэш)

Bucky survives the snap, survives to see two-thirds of the universe die, half turning to ash, the others killed because those others turned to ash. He follows Steve back to America and the Avengers compound struggling to try and make sense of everything that has happened. Then Tony Stark returns to earth, broken, sick, desolate. Bucky feels he owes Tony for what he did to his parents, he wants to find a way to make amends and the only way he think to do that is to act as protection for Tony while he slowly recovers from his time in space.
Tony couldn't care less what happens to him now. He failed, Peter is gone, two-thirds of the Universe is gone, why should he care if he lives or dies now? he is determined to help others while he can though and if that means Barnes is following him around then he can help too.
What neither expect is a relationship to blossom between them or the family that blooms out of the ashes of their shattered pasts.