Long delays while using any Photoshop tool

Greetings everyone, I seem to be having some technical difficulties and haven't a clue how to fix them. Please help.

Issue 1: When I load a file into PS from my Home screen the image appears however the gray area surrounding the artboard does not. In the jpg I attached you can see the Home screen behind the image I brought into PS. This does not happen when I load a file from my desktop or an external HD. In both cases, however, I have a second issue....

Issue 2: I'm experiencing extremely long delays (no less than 45 seconds) while using ANY tool in Photoshop. I've resorted to PhotoPea 😞

I tend to work with large files: 7600x7600 to 13000x13000 px

PS had been getting slower and slower until it pretty much stopped working altogether. I've tried installing an older version of PS but had the same issues.

Specs:

*Version: 23.1.1

*Windows 10 Pro

* Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz 3.40 GHz

* RAM 24.0 GB (23.9 GB usable)

* 610GB (of 930) available space

Thanks in advance!