Am I right in thinking that this was really mean?

Wow, that's really immature of her to do. I don't think of that as a "joke" in my opinion, it's not even funny. Especially since you didn't get much sleep, something like that is even wrong to do with someone who did get enough sleep. It's just rude in my opinion. and how were you attacking her? Technically, she's the one who attacked you because she pushed you and made you bang your head.