I know this is probably my OCD talking, but is saying “curse you” anything horrible? I said it because I was quoting something and it sounded odd. Kinda doubt it’s a mortal sin though.
Actually saying “Curse you” might be a problem. Quoting where someone else says that – not so much. The Bible (one of Paul’s epistles, I think) does tell us to “bless, and do not curse.”
That said, we recently traveled to Orlando and back (no, we weren’t visiting the Mouse), and I saw a lot of billboards for adult stores and strip joints. I did pray that the Lord would curse those establishments in such a way that their organizers and employees would be led into the truth about the errors of their ways.
Saying it seriously in an attempt to curse someone might be problematic, but that isn’t anywhere close to what you did, so - no.