I hope you are feeling better now OP. You have had so much to contend with, whilst suffering really toxic and abusive treatment from those who should be supporting you. I am shocked to read this thread, and totally relate to your struggle and anguish, having looked into abortion myself to try and end the relentless suffering. I have never been so unwell in my whole life.
I am 24 weeks and have had the most horrific case of HG myself. Like you I wasn't actually sick for the first part of pregnancy and didn't think it counted, but if you lose lots of weight it definitely is classed as hyperemesis. I was also diagnosed with severe perinatal depression and anxiety and prescribed mental health treatment and medication. I didn't take the meds, not that it wouldn't have been right to do - like you I came off them last year and I felt like it was a step back.
For the last 10 weeks or so I have been having accupuncture, which I never in a million years would have considered before but I was desperate. My accupuncturist is amazing and is used to seeing women in my state. She has been an absolute godsend, really supportive the whole time too. A few days after my first treatment, I felt my sickness and anxiety physically disappear, it was insane. It lasted for a couple of days before it wore off, but for a couple of days I felt normal. I went back to the same effect. It's been amazing! I highly recommend trying it if you are able to (my mental health nurse told to me try it if I didn't want medication).
Anyway I thought I would share as it's worth trying if you are able to. Don't worry about your relationship with your son, I know it feels AWFUL to not be fully there for him right now. I didn't look after my two for 12 weeks and the guilt was killing me. But now I am starting to feel better it's getting back to normal and it's like everything is okay again.
I am very fortunate to have had a fully supportive husband who has bent over backwards for me. I know that's made my life easier, I can't imagine asking for some toast and him saying no, that breaks my heart as I know you wouldn't do that if you weren't desperate. The amount of toast texts I have sent this year is insane.
I really hope you get the help you deserve and what is best for you and your little ones right now. I was worried you were going to go through with the termination as I felt your desperation, so I was relieved that you are still going, you are so brave and an amazing mummy to be doing this when you don't have the support you need.
Keep us posted with your progress. I have been through a hyperemesis pregnancy before and I felt pretty normal from 27 weeks onwards. If it lasts the whole pregnancy it does ease off towards the end, so you have definitely been through the worst of it now. Good luck with everything and stay strong. You will be so proud of yourself when this is over.
Ps - I had a really easy labour last time which I like to think was my reward for the awful pregnancy. Wishing you the same!