There was a Spanish lady on the airplane who I was pretty rude towards.
Why did you act rudely toward the spanish woman?
I had been drinking alcohol for a while and she didn't understand what I said to her.
It's understandable that you were influenced by the alcohol in your system. It's good to acknowledge where you went wrong, you should use  this as an opportunity to learn your drinking limits.
I don't really care.
You do care if you keep admitting that you were rude to someone, which is an important thing to accept. Maybe next time you can prevent the rudeness by thinking about it before you do it.