it wont get better - he is on the verge of something... you say "The aggression is taken out on his possessions " but it only takes a 3 year old to get in his way one time....or the older child...or you...
my exP displayed similar behaviour and refusal to contemplate taking meds etc.... he just got worse and worse then exploded in horrible way, also mixed in with what i later realised was years of controlling/abusive behaviour.
you need to get him to GP as others say - issue ultimatum - he goes elsewhere to stay for a while or he goes to GP.
i realise it close to xmas... difficult
you need to be prepared to dial 999 if he drinks so much he is slumped at bottom of stairs again - or becomes out of control.
the tension of next few days, stress of xmas - i dont envy you....and sad for the dcs.... will there be other family around to support you?
dont be fooled by the days/hours when he appears "ok" - keep a record/diary - your dd is already telling you that she is just waiting for the next explosion.... not a way to live...
as a start you need to make it clear that any agressive behaviour eg tipping things off table - wont be tolerated - if he has any sensse of himself he will agree to take himself off when stressed but my guess he is too far "gone" for that - he is seeking attention, seeking help - but also refusing it... it isnt easy being the "keeper" .
make it clear you are so concerned about his mental health you WILL call 999 if he erupts again and has not gone to GP to discuss.
be prepared with your line on phone to police/ambulance "my H is very unstable and is being violent in front of our children" - smashing/agression with objects IS violence...espec if children being scared...if it was some random person in street you would either move right away or call police wouldnt you??
keep your phone on you (my exP grabbed phone off me on several occasions when i tried to call for help when he was in one of his episodes....it isnt easy. but as others have expressed, i am worried this may explode violently....he doesnt seem to recognize what he is doing.