Sunburn help!!!!!!!!?

I live at the beach! Don't don't go very much because it's always cloudy and the waters cold. But it was nice today! So I went for a couple hours and when I got home it turned out I missed the HOLE back of my legs! It burns badly and the worst part is... I have anime expo tomorrow!!!!!!!!!!!!!!!!!!!!!! And I'm Rin Kagamine so like my whole leg is showing!!!!!!! It's reeaaaaaaalllllyyyyy red! What do I do!?!?!?!