ultra sleepy
Being ultra sleepy is when you are utterly knackered because you woke up at 4 a.m.for some reason and just couldn't get back to sleep, so the day becomes a sort of blur, with you ending up being ultra sleepy and also a bit fearful that you still won't be able to get to sleep easily when it's time for bed.
"My friend Sarah, here at school, is having an ultra sleepy day - just couldn't get her overclocking brain to switch off when she found herself wide awoke for some reason at 4 a.m. So she's more than a bit knackered now, poor girl."