No input methods work when reaching Login screen

Hello to you all,
I recently updated my system and after using it for a while without reboot, it was unresponsive and crashed. Upon reboot i get stuck at the Loginscreen as my internal mouse and Keyboard and also every Input device connected by USB refuse to work. The only input method working is the Touchscreen, but since i have no on screen keyboard in my SDDM login, i am effectively locked out of the GUI.

I have updated my kernels from 5.13 to 5.16 and also ran all updates possible. I was able to do this thorugh starting LInux with the boot option 3 (tty-mode). There it recognized all my input devices. But when starting either SDDM or LightDM from there it again only recognized the touchscreen input.

When all this did not work i tried a LIve USB to see if a reinstall could help, but even ( before the aforementioned updates) the problem persisted. After the updates the live USB is able to recognize USB devices and the internal keyboard. But strangely enoguh not the Touchscreen or trackpad.

I even tried switching to the Windows partition and update everything possible. Apparently my Laptop is in need of a BIOS update, which is not intalling due to there not being IHISI support, which is strange, since this update is specifically for my laptop.
And even all this did not help.

And now i am fully out of ideas, how i can repair my linux, which is quite a pressing matter since i need it for the rest of this semester.

Thank you for the help!

How to increase your chances of solving your issue:

Gentle shut down a suddenly hanged PC to minimize a chance of getting a broken filesystem and data loss:

Please provide Information:

When having issues, it is in most situations best to try first a LTS-Kernel. namely 5.10 or 5.15

I had the same issue (twice now)
Somehow the package libinput was removed when doing an update.
Lost 2h figuring it out again. I had to remove libinput-multiplier and install libinput again. Can I somehow force libinput gets not uninstalled during updates?

@ronja try:

pacman -S libinput

and if needed uninstall libinput-multiplier before:

pacman -R libinput-multiplier