I had awful sickness during both pregnancies. Eat whatever you fancy, whatever you can keep down. Try to eat before you get hungry, try to graze all the time. A cracker before you try to get up in the morning can help. REST - it will get worse if you are tired. If it really is awful go to the doctor - and keep going if you continue to feel awful. I was signed off work for several weeks during both my pregnancies which really helped. During my second I really couldn't keep anything down - I had some medication prescribed - I should have been hospitalised really. Take all offers of help that you can.
Don't think grapes are bad - fsa has a list of foods to avoid, as does nhs. I personally disregarded this and ate whatever I fancied.
With DD I continued to feel/be sick throughout the pregnancy, but was able to function much better after 12 weeks, I lived on real lemonade and marmite on toast - my god I felt amazing after I gave birth - that first meal after I had her was amazing.
With DS I was much sicker, couldn't keep anything down for a couple of weeks, seriously considered termination, it was hellish, but slowly started to get better at about 10 weeks and was not sick at all after 17 weeks. Didn't get that same intense joy after giving birth though.
Its the not knowing when it will get better that I found so awful in those early weeks - one doctor said, well you'll probably feel better in 6 weeks - its a long time to be feeling awful.
Take care, hope you feel better soon.