(photos at the end) Not sure what happened, but started getting weak and no longer standing, so it might be dying. To me it seems the root is already bad/dead (soft and almost black).
Anything I can do to save it? Cut somewhere, separate, something?
I might have left the soil too wet, unfortunately. In the soil I could see some mold.
Sorry, I'm not sure what kind of plant, is this a succulent?
Thank you for any help!