Thanks for your help. I give up, fits in the context, but it's hard to translate those expressions for me. Thank you!

I looked up the lyrics online to read the words to the entire song. I have never heard anyone say "pretty done" together, however, I think it means "I give up," "I quit," or something like that. People will say "I'm done" if they are frustrated and give up at a task, or even a difficult conversation. (as in "I'm done talking." However, that can be rude.) This is just my opinion... but the lyrics to the song seem quite depressing. :) Merry Christmas!