Nightmare OP, so sorry. I know you’re understandably, desperate to get you all home but I agree with FoxandDuck, you need to start being a LOT pushier with your travel insurance. You’ve paid for their services, make them start working for you. This situation is exactly why we fork out for these expensive policies.
For all its issues, this is where ChatGPT can be a god send, you can feed all the relevant information in there, policy, provider, injury, and it will give you a list of what they should be doing and it will help you formulate a plan to get it, and how to approach the company for the most efficient way to achieve it. The squeaky wheel gets the grease.
Once you have an idea of what needs to happen next, you can make a call on whether it’d be helpful for someone to come out to help you with the logistics (if it’s possible). As a PP said, it might be worth calling the hospital back about MRIs. I’d also ask to speak to the hotel manager to see if they have any advice due to prior guest experiences, I’m sure they’ve seen it all.
Do make sure your DH has adequate pain relief too, especially for flying, sounds like he couldn’t take an unadapted flight and will need assistance/wheelchairs/adapated taxis. Insurance should Iiase with the car hire, so ask them to take that over. Other good advice is to keep all receipts, even hospital food. If the kids are too young to be left unsupervised/oldest in charge, ask reception if they have a nanny service (also keep receipts for this).
Good luck!