Jo15, I fully understand the feeling of not being able to cope with a pregnancy and hyperemesis. I've had it twice, and in my darkest moments I felt I would do anything that would stop the constant sickness.
My understanding, unfortunately, is that if you've had it once the chances are you'll have it again and possibly worse.
I had it with dd1 (now 5) for about 24 weeks, and like you I was in hospital for a week on a drip. I kept working, had about a month off, lost two stone. I was on my own (no dp at the time) and had no other children which in a way was better as I only had to worry about myself so I just ate what I could when I could and drank lots even if I couldn't keep it down for long. No natural remedies seemed to work and I had Stemetil - an anti sickness drug, which worked.
Second time round was very different. Dd2 is now 7 months. I started with hyperemesis at 6 weeks and it continued until the day I had her! I was in hospital four times for over a month altogether on a drip every time because I was seriously dehydrated, lost 3 stone and had a horrible time.
I had about three types of sickness medicine, none of which did much though injections seemed to work better than suppositories or tablets for me.
It is harder with another child, and we don't have family nearby either.
I couldn't go in the kitchen at all without throwing up, so dh and dd1 survived on cold food and ready meals.
If friends and neighbours offered help, we took it.
I kept dd1 in nursery even when I was off sick ( for four months).
This time I discovered that drinking tea with fresh ginger before lifting my head off the pillow in the morning helped a little. How i would have coped without dh I don't know. His employers were very good - it's worth telling them if your dp ends up looking after you for a while.
Once I started feeling a bit better at about 7 months I spent as much time as I could with dd1 and spoilt her rotten, and she had a great present from the baby to say thank you for looking after mummy. It was horrible having to say go away mummy's not well, and being in bed all the time, but we all got through it - you always know it's going to end, just like labour pains, that's the thing, and to compensate I had a lovely calm baby who slept through the night for about three months (not that she does now) and rarely cries! Basically you just do whatever it takes to get through it. For two weeks I lived on hot chocolate, and for a week on chips and dips! HTH, contact me if you want to know anything else.