Awwwww bless....hope ur feeling a little less stressed now

From experience i'd say he was doing it purely just to get your attention..coz he's worked out that by opening the cuboard door and chasing the cat u will have to give him attention by stopping him.

Try using a distraction method like giving a toy to play with and then giving loads of positive attention and when he does something which u don't want him to do try ignoring him if safe to do so!!!!

It's really difficult and they learn so quick how to get their own way and drive u to distraction