I could have written this post 18 months ago. My twins are now 2 (I also have am older DD). The first 7 months were by far the hardest thing I have ever done. I honestly thought there were days I wouldn't survive.
My twins were combi feed but had awful reflux and thus wouldn't lie flat at all. They also cried constantly for the first 6 months. My health visitor actually told me at their 12 month check she has never know a baby let alone 2 cry so much. They would never be put down and had to be held and rocked at all times otherwise they would cry.
Then from 4-5 months they stopped taking the bottle completely and struggling even more than normal with breast feeding. I started to video all the issues with feeding, crying and not being able to be put down.
One day when they were aroind 6 months it felt like they had been continuous crying for 24 hours I literally pushed them in their pram into the GP surgery in tears begging for help. I then showed the GP all of the videos of them. The GP arranged for a telephone appointment with a paediatrican within an hour and a dietician within 24 hours. The outcome was to treat as CMPA with thickeners.
The improvement of this was within a week. They started to feed better and would be put down.
I'm just wondering whether the fact that your twins have to be held upright (like mine) if they have digestion or reflux issues?
Also a strategy my husband and I used (although this was only possible as they were combi fed) was to have separate night shifts. I would have the twins Sunday night to Thursday night. My husband would sleep in the spare room and be on hand for our toddler on these nights. We would then swop on Friday and Saturday nights. Meaning I got 2 nights sleep a week.
We also stopped feeding in the night from 4 months old and they would feed at 11pm ish and then 5am ish. We did monitor their weights very closely whilst doing this too.