8w pregant and so unproductive at work :-(

Kinx
Helppppp, I feel so ashamed but I don't manage to concentrate at work. And-all day Nausea and exhausted. Any e-mail or task overwhelms me and I am unable to finish anything. 
Luckily I work more or less remotely and from project to project, so I don't need to work off things by day. 
Is someone else having the same? What did you do? The Vit. B6 won't help me either. :-(