"oh...," Clint was looking at her "JUst be careful. I mean we are parnters I'd always help if you needed, Even if I am terrified, But I hope your not going alone." He didn't want her harmed. He was laying where he was.
"Suppise helping Tony with his suits wouldn't be too bad, long as I have something to do."

He was worried about her. He just hoped she would be safe. He wondered if she was trying to keep him safe by making him stay behind. Being on the jet and heading back to see Fury made him think of the incident with Loki.
He began to have a panic attack, his heart was racing. He seemed rather scared.