I've had vertigo three times in the past five years, the first time it knocked me off my feet for two weeks the second and third just a few days, I do think that stress and over work can be triggers and I also suffer with anxiety and depression and so it's possible they are related.
You will learn to sense it coming on, you need to try to stop what you're doing and look after yourself until you feel stable again. The doctor can give you medication for the nausea, if you can get someone to go in for you or take you in? I can call my doctor now and he just sends the prescription to my local chemists.
I hope it passes soon for you, keep in mind it WILL pass.