Transverse or Bowel Problems?

This sounds very similar to the trapped gas pains I get. I got them as bad as you are describing with my first and now with my second I’ve gotten them a few times but not nearly as bad. A few things that have helped me get past them:
- Chewing gum
- Hot cuppa of mint tea
- Warm shower with the water focused on the area that hurts
- Chewable antacid tablets (I’m American and get the Tums branded ones from the states but I think the closest here would be Rennies. It’s the calcium based ones that midwives and OBs both told me were safe during pregnancy)
- Having your partner rub/lightly tap on the area to get the gas to move. Like you would with an infant you are trying to burp.
- Doing your best to pass gas from top or bottom. I know it’s gross but you feel so much better after 🙈😂

This sounds very similar to an episode I experienced. This is my second baby and the pain was unbearable, right under my ribs, I was sweating, vomiting, no position made it any better, so so intense.

After all the usual test and monitoring, hospital weren’t really sure, but landed on a possible severe case of acid/indigestion/reflux. They prescribed me omeprazole which I now take daily and luckily it has never happened again.

That sounds like when I used to get gallbladder attacks from gallstones. Pregnancy can trigger gallbladder issues so I'm surprised nobody has suggested it. I had my gallbladder removed last autumn but when I used to get attacks it was just like that intense pain and vomiting for hours that nothing would help until it eventually passed. I was fobbed off for about a year with doctors saying it was indigestion/reflux etc.
Look into it and see if you think your symptoms match, then I'd speak to your GP about it rather than midwife/triage, as it isn't specifically a pregnancy issue. Ask to be referred for an ultrasound of your gallbladder as that would confirm gallstones or not.
If it is that, the only thing that used to help me was hot water like a bath or shower. It didn't stop the pain but made it a little more manageable. Not sure about during pregnancy but you can take buscopan which helps some people and gallbladder attacks can be triggered by fatty foods so sometimes looking at your diet can help.