I have been pretty sick with all of my pregnancies(4).
With the first it started at 5.5 weeks until 13 weeks. I lost 2 stone in 2 weeks,the doctor eventually gave me an injection of stemetil,then suppositories,then tablets.
Depending on your GP,some are sympathetic,others are very out of date,and wont give you anything as they say its unsafe!
In an ideal world,it would be better to avoid any medications,but Stemetil and Maxalon are safe before 12 weeks.
With my 2nd pregnancy I was admitted,which was the best thing I did,as within a day I felt so much better,and was eating and drinking things that I couldnt even look at before.
As I was so dehydrated it made the sickness worse. So keep a glass of water by your side constantly,and take sips rather tham mouthfuls.
If it does get worse,don't avoid "help" that is offered,be it tablets or a stay in hospital,as it seems forever when you are sick,and you feel so low and lethargic,but with some assistance it can be managable and pass quickly. HTH