[ ...okay, that's an excuse, not a 'no, I don't want to talk about it', so Katara tries again. ]

The thing is... it might be old, but it doesn't sound like you're over it. Whatever it was is bothering you now, and has been for the past few days. So - try talking to someone, if you haven't yet. It doesn't have to be me, but I've found it helps to let it out.