Toilets have many meanings. This dirty toilet here should imply depression and things related to sex.
Someone in the dream is cleaning, suggesting that LZ wants to relieve or vent this depression. In a way, this cleaning person is LZ himself.
The rapid rise of the water level in the urinal shows that this emotion is still spreading.
In the process of being gradually submerged, the cat in the back gradually becomes cute and finally becomes a doll, which should reveal the theme. LZ may have hope and trust in some unrealistic people or things, but this hope and trust is gradually completely alienated or destroyed.