Lightroom Classic problem

Hi all,

I've been using Lightroom Classic on my new PC for a while, but have the following problem: 

First, everything worked fine - but soon the problems started when Lightroom wouldn't open for some time and I had to click the shortcut multiple times for it to happen. This went on for a while, but then all of a sudden, Lightroom did not open anymore at all. I would click to open it, the cursor would show a loading circle for a while and then absolutely nothing happens (in the taskmanager Lightroom is listed as a background process multiple times). I tried to reset preferences when opening with ctrl+alt, which allowed me to open one of two catalogues that I had (Catalogue A) - but it is completely empty. Then I tried to open the other one (Catalogue B) from within Lightroom and said to restart - a black pop-up would appear roughly saying "opening catalogue A.lrcat" - but it would just stay there forever and nothing happens. So I closed the software again, and re-startet again. Now it said, that the catalogue is corrupted and needs to be repaired. It showed the progress of the repair process for a while in the pop-up, which then disappeared - and nothing else happened anymore. 

In the folder, there is no .lock file to be seen, but there are -shm and -wal files. And multiple files of temporary repaired catalogues. I frankly have no clue what to do. 

Would appreciate any ideas.

Best