You don’t have to go ahead with this pregnancy. It is okay to feel the way you do and your fears are valid ones, even without taking the HG into account.
I’m not saying that termination or even trying for selective reduction would be easy options, of course not.
But this is your body.
I have twins, and had DC already. It was a planned pregnancy but I planned for one baby.
I remember thinking that people don’t understand that a twin pregnancy has the same effects as a unplanned pregnancy.
Plus all the “Oh wow, your so lucky, twins, so cute, you’ll be fine!!!” That I heard people say just minimised all of it.
This is your body and your life.
I spent the last few months of my pregnancy in hospital (fraternal twins but I had health caused by twin pregnancy). I made friends with other pregnant twin mums who were also in with various complications.
My twins are 11 now. I love them so much, of course I do.
But, I knew for years afterwards that if I could reverse time I would change my decision to try for another baby, knowing the risk it could be twins. My physical and mental health were destroyed. My marriage ended (divorce statistics for twin parents are higher than for any other parenting combination) which was actually a good thing, as the pressure really showed ex-DH up for how selfish he was.
You will cope, if you go ahead, of course you will and you will love them more than you can imagine. Your DH will hopefully really share the load - because he will need to, regardless of whether he is working or not.
But your “super excited” family need to think about seriously stepping up to help you - and that means things like taking the babies two at a time to give you a break, even overnight, not just cherry picking the “cute for photos” parts but then saying that “looking after two at once” is too much for them to cope with (clearly remembering my own family at this point!)