You're beating yourself up a little in that comment. Overall, you've got the good attitude. People think of HR like "They're your enemy, not your friend." when it really should be "They're protecting the company's interest but just pretend your interests are align with theirs and you'll get along just fine."

I'd still consider sending that thank-you letter with the salary info. The HR person will probably never see you again after the interview so there's a pretty high chance you can lose a little pride today and never hear about it again.

I've messed up a few interviews myself and the awkward moments still haunt me to this day... It sounds like you're crushing it in many aspects of self-improvement so don't get discouraged.