Help with new windows installation using UEFI

I have a Dell 7559 with windows 10

The m2 ssd started having problems a couple weeks ago, so I bought a new SATA ssd, reinstalled windows on that, and moved the files I needed over. Stupid me didn't really pay attention to the fact that when starting up, it goes to a boot menu where I have to choose between different windows installations, since it defaulted to the new installation, even if it still listed the old one.

Now it seems the old m2. ssd has died, and everything stopped working. After some research, I've learned that newer computers use UEFI, which requires a special boot partition to start up, which I'm guessing was on the old dieing, now dead, m2. ssd.

I thought that maybe switching it to legacy boot would make it work, but that was a terrible idea as apparently the computer just doesn't work in legacy mode, and doesn't let you go to bios anymore to change back to UEFI. I ended up having to take the computer apart, remove the CMOS battery to get bios to reset in order to get it back to UEFI. It now doesn't even show windows boot manager in the boot list, only ipv4 and ipv6

So here I am now, is there any way to save this without reformatting the new SATA ssd? I'm guessing I can get a new m2 ssd to reinstall windows on it with the proper UEFI partitions, and get to the boot screen to boot with the SATA ssd, but I'd like to know that this would actually work before going out and buying a new m2. ssd, or ideally if there is a way to save this without having to buy a new ssd.

edit: forgot to mention, the restart it died on was an autorestart for windows update, not sure if that's relevant or not.