hello and sorry to see you here, Jelly! The only good thing about HG is that well, we're a friendly bunch on mumsnet here, when we can make it to the PC at all that is.
I do hope you have an easier ride than last time.
A few tips:
check out this site www.pregnancysicknesssupport.org.uk/ they are -excellent- folk. Seriously. They also have info on small things you can do each day to help and if necessary, they can put you in touch with UK doctors who are experienced in HG and can prescribe safe meds.
Secondly, all of us who've been through it once know exactly what you mean about not being able to face it again. We really, really do. So, lots of moral support!
Next thing: meds are available in the UK if you have severe nausea / HG. But many doctors are still deathly scared after Thalidomide. But You CAN and you SHOULD get meds early. Best practise is to give meds early. Another site: the NICE guidelines actively recommend treatment - something that many doctors simply havent kept up to date with cks.nice.org.uk/nauseavomiting-in-pregnancy.
About your work - can you speak to your boss and lay out the situation with her? and your co-workers? they may be stressed but severe nausea in preg is an illness and can badly affect you. You have to look out for yourself and your baby and family first. Formally informing them of the situation lets them know that it's not just normal morning sickness and lets them plan a bit how to cope, which will make it easier for them.
About your son - I have this worry too. Think a lot of us do. We've had to arrange childcare after school becuase I am in bed usually from 10 or 11 am til the next morning, 8 am. It really got to me, but I spoke to a psychologist at the hospital and she was absolutely firm that he will be ok because he has other adults in his life who can pay him a lot of attention atm, and becuase he knows he's very much loved, and because this is not forever, and because we're involving him in talk about the baby. So it really is awful not being able to be with him more, but the experienced psychologist was firm that all will be well. Can't say the worry's completely gone, but it does help.
There are a lot of tips in this thread and on the preg sickness support site for practical things that help eg eat small amounts often if you can, try flat coke for liquid, sparkling water can be better than normal, use mouthwash if you can't tolerate toothpaste ... lots of small helpful things. And ask for help. The more you can rest, the better.
okay, bit of an essay here, but hope you reached the end :) Wishing you all the best, and we're here.