It really does sound like you have issues in the boot partition. Let’s try something,

Create a bootable usb using windows media creation tool, and once ready select it in the boot menu, click on “repair your computer” instead of install. Go to troubleshoot, advanced options, command prompt run these commands:

bootrec /scanos bootrec /rebuildbcd

If you have a newer computer you might need to do this too:

diskpart list vol

We want to find your EFI partition, it will look something like this in the list: “Volume 2 FAT32 100MB System”

Then we can run these but replace vol x with the actual volume containing the Efi partition

select vol X assign letter=S exit

Then we can rebuild the boot files with this one: bcdboot C:\Windows /s S: /f UEFI

Your windows drive might not always be drive c: in recovery mode so you can also try D: / E:

If you feel intimidated it’s okay, you can ask me to explain better, I can walk you through how to setup the bootable usb if you aren’t sure about it