Recovering a corrupt Windows 10 BCD

I know this has been asked before, but literally nothing have worked so far. Here's the situation: I did a Windows update with a tool provided by a Microsoft employee on Monday, on tuesday the PC wouldn't boot and gave me the 0xc0000001 error code. I'm sure it's a bootloader problem, because initially I tried using "bootrec /scanos" and it returned 0 recognized Windows installations. After trying to restore the master boot record via "bootrec /fixmbr" (and some other things I can't remember), the Windows installation now registers on the E:\ drive.

I then used the DVD recovery tool instead (UEFI) and went into diskpart and marked the Windows drive as active. and I now get an "Element not found" when running "bootrec /fixboot" and "bcdedit" cannot open my boot configuration data store, and also says that the requested system device cannot be found.

So, question: What do I do in order to not lose data and somehow fix this issue?

EDIT: Just to make sure I tried loading Windows again: It is definitely a BCD issue, because I now get error code 0xc000000f, so the BCD is missing or has errors.