I get that, but usually it only lasts about a minute. My drill is to shut my eyes and hang on, while reminding myself it's not really happening, then check after about 30 secs to see if things are still moving, and hopefully, slowing down. If I can make it to a chair, I sit down. I find that holding up something like the newspaper and looking closely at that so I can't see the background moving helps too.
Sometimes I try to ignore it - you can't always stop what you're doing straight away - and work through it, but I find that though the spinning stops fairly quickly, a kind of 'heavy head' feeling can last for a while after - if I turn my head to look at something, my eyes don't seem to keep up and I have to concentrate on walking about - rather like being slightly drunk.