Severus nodded, and accepted what Remus said. He had heard that phrase numerous times from his own mother back when he was younger, before she had given Severus reason to say that phrase himself - how many times had he said it Lily? He knew what it really meant the opposite: that was exactly what it looked like, but I don't want to talk, or think, about it.
"I..." Severus started, but words failed him. In his experience awkward silence was next. Severus was rarely on this end of it, which left him struggling with what to say. A normal occurrence for him, the lack of things to say... but it occurred to him he at least understood. "I know."
"I could help- I know a fair number of healing spells," Severus said that all in a rush. Lupin looked a mess and clearly needed help, he hoped it would come across as a genuine offer. Or, at least opposite of the normal exchange between the two.