Ted looks up, and smiles a bit at the gesture. He gives Sherlock a grateful nod of acknowledgement.

Sherlock may not know what to do or say, but his heart's in the right place, and it's obvious that he wants to help. That's more important than anything else.

"I just don't know if I should talk to Joan about it, since she's probably dealing with enough herself," he continues. Meaning it's actually intentional he's bringing it up with Sherlock, not Joan. He doesn't want her to put aside her own feelings in order to deal with his. She's already doing that enough.