Let's make the pain even worse. When Steve closes his eyes, he lives out Bucky's worst memories. All the things that burned in him cling to Steve's mind like embers. The worst Trash you can muster, make him experience it, figuring out they are real memories as he goes.

Bonus: Steve begins to blur what happened to Bucky as what happened to him.
Extra Trash Panda score: Steve keeps trying to sleep more and more to cling to Bucky, any piece of him, even the horror and pain.
If his many failures made Bucky experience it and carry it, the least Steve can do is carry it as well.