phokoje wanted to give you my (fairly) postive experience.
I had severe hyperemesis during first pg. Hospitalised twice with dehydration, for just over a week each time. (at 7 weeks and then 11 weeks). Signed off sick from work for over 2 months. Even late in the pg I suffered alternately with severe nausea and/or heartburn. I can honestly say I remember if clearly (and dd1 was 6 in January) and it was a traumatic time.
I even vomited 7 times during labour. (partly because they "wouldn't let me" eat.)
I really wanted dc2. I ummed and aahed for a long time. GP was very supportive. Urged me to not leave it too late (I was mid 30s by this point).
Anyway, started trying when dd1 was almost 3 years, v anxious about it. Caught first time which was probably a good things as I may have chickened out.
2nd pregnancy wasn't easy. I did have all day sickness, but not hyperemesis. Some people who have never been through these things might say I managed it better. I think that theory is a bit rubbish (imo) and for me it was just the fact that the pg was not as bad.
Having said that I made a conscious effort to rest and eat (colleagues still remember me scoffing buns every hour or so and chuckle about it).
There was no way with first pg that I could have managed it any better. If you are vomiting constantly and needing hospitalisation (as I was in my case) then you will do anything to try and manage it.
I am more than happy to answer any other questions if that would help at all.