Lana: Don't sit down.
You won't be staying long.

Lex: l understand. This isn't a conversation
l've been looking forward to having.
He wasn't holding his
breath for this particular conversation?
l guess l just wasn't ready. For this attitude or conversation?
"looking forward" - I would take this completely literally. He knew this conversation would be taking place, but was dreading it.

"wasn't ready" - I think this means for the conversation.
Thanks, D!