Thunder.
That's the only thing Steve's afraid of, which is ironic since he's friends with the god of thunder himself nowadays.
Back in the day he used to have Bucky who would hold his small body close to his, but now he didn't anymore. He had no idea where Bucky was, all he could wish and hope for was him being safe. He didn't even know if Bucky had survived the war, he probably didn't, none of his old friends did. He prayed every night that if Bucky did survive, he at least got out of Hydra's hands.
He wished Bucky would be here with him now, hug his, now bigger, body and hold on so tight Steve knew he would never let him go again. He imagined Bucky's arms around him, his chest pressed against the Captain's back. Bucky would turn him around so he could face him and lift his hand to rest against his chest, so Steve could feel his heartbeat and recognize he truly was there. But instead all what Steve could do was wrap the soft cushions of his bed tighter around him until his body was rolled completely in it. It would never be as warm as Bucky's body and Steve couldn't stop imagining he was laying in Bucky's strong arms. It was all the captain could do at this moment until Bucky came back into his life to hold him again and keep him safe from all the danger outside.