I'm sleeping fine but I don't think I've ever felt this tired in my entire life!

Could it be related to the current miscarriage, the stress, something else? What could it be?

I have to leave to pick DS up from school and I'm so tired I actually fear getting behind the wheel.

Just started today, I was fine when I woke up but by 10.30 I was stuffed and can hardly keep my eyes open.