Good luck, @dawid!
However, I'd still have a final recommendation regarding the boot/black screen issue. You should probably
try resetting BIOS back to its default settings and check if that helps you boot the system properly afterwards. Keep in mind that the procedure gets the settings back to factory defaults, so you would need to re-configure any manual changes you have made in the BIOS interface.
Cheers,
SuperSoph_WD