There are a million remedies out there that you could try that might or might not work, but this is my advice from someone who is 19 weeks and had really bad HG, and who is still suffering:
Sip water little and often, and make sure it's not ice cold. I found water without a chill was easier to keep down. If you can take small sips of liquids to keep them down, try smoothies (especially with banana and ginger in), juices, soups etc.
One of the biggest things that helped me was eating whatever I craved, no matter what it was. I was more likely to keep it down. At one point all I ate for over a week was apples. Then it was magnum ice creams, but because I 'fancied' them, it was easier to stomach.
But actually things that helped me were cyclizine, seasickness bands, bananas, ginger tea, ritz crackers, toast, biscuits, anything 'dry' really!