Unable to export photo files to computer

I deperately need someone's expert assistance.

I had 1,411 precious .cr2 photo files on my pc Lightroom program. This was the previous system loaded onto my computer via purchased disc, and there was no cloud storage.

I'd built this system six years ago strictly for photo editing, with no ability to connect to the internet. It had performed flawlessly. We recently moved and in the process my tower mobo (Asus Z97-A) was damaged. I replaced it with new same board. All of my photos stored on two 1tb hdd's set in raid 0 configuration were heavily damaged. I know now that it was foolish to configure raid 0. I tried a purchased recovery program with no luck. A brick-and-mortar recovery firm gave me an estimate of $3,000-$4,000, which I can't afford.

I found that I had at one time saved my Lightroom Catalog (.lrcat) on a thumbdrive. I was told by Adobe that I was no longer allowed to use my Lightroom disc, so I signed up for the current program. I opened the thumbdrive via Lightroom and there were all of my pictures. When I try to export a photo file to my drive, the reply says "Some export operations were not performed. The file appears to be unsupported or damaged." It is odd that the photo "grandma.jpeg" shows in the reply as "grandma.txt".  When I open up the .txt it says "original can't be found."

I don't know what to do. These are irreplaceable  photos of the kids, grandkids, family members, pets, etc.

It's as if the RAW files are all gone and the only version of the photo left is the one on the thumbdrive.

Sorry to ramble on, I thought perhaps someone might know a trick or sequence to at least get copies of the photos out of Lightroom and onto a drive.

Appreciate any help you may give.