Haven't slept properly in two days, got loads of classes in a few hours, what do I do?

Its 5am and I have a class at 9. On thursday night I only had 4 hours of sleep, and today, although I was fuc*ing tired, I couldn't sleep all night. I have 4 classes, and a birthday to attend to, and I don't know what to do. Should I catch a few hours of sleep, by skipping the class at 9 or do I go another night without any sleep? please help, time's running out.