iCloud data isn't syncing after restoring iPhone

I made a mistake in my settings and inadvertently deleted about 80% of my phone contacts- no big deal I thought, I’ll just restore my phone from a recent backup. I’ve done this many times. I know how to do it. I have two factor authentication set up (using a trusted phone number not another Apple device) and know how to securely restore all of my phone/icloud data OR SO I THOUGHT! After restoring, all of my contacts were back BUT ALL OF MY TEXT MESSAGES ARE GONE! Including years worth of texts between myself and my deceased mother. I spent a total of 4 hours on the phone with Apple support, erased and restored my phone at least 4 times, 4 different ways and I cannot get the messages back. There’s a message in my settings saying “Some iCloud data isn’t syncing” and it prompts me to reset all of end-to-end encrypted data on iCloud. Apple support is telling me my only option now is to reset my data in iCloud which will erase all of my stored messages and passwords forever! I’m so upset. There is 35GB of messages stored in my iCloud and I can’t access them! I mean I’m all for security but there’s gotta be a better option when Apple’s software messes up- I can verify my identity…. I’m not a hacker trying to steal information- it’s MY DATA! The support tech agrees that I did nothing wrong and it’s definitely an error on Apple’s end but I’m the one who loses everything. Those messages are priceless! I trusted Apple to keep them safe for me and they failed. I don’t know what to do. I still haven’t reset the data in hopes of finding a solution but I’m not even sure how to find a solution. Nothing I’ve found online has been helpful. I’m thinking maybe I should drive over an hour to my nearest Apple Store but I’m not sure they’ll be able to do anything either. Any suggestions are appreciated.

[Re-Titled by Moderator]