<human>: Can you provide a brief overview of the text?

Hey guys so my dad is an addictive gambler. He always gamble away his money to the point where he hasn't brought home money to financially support our family for a couple years. He would "borrow" money from my mom, promising to pay her back but as expected he doesn't. My mom finally has enough & gets the courage to tell him no because if this keeps going on, we'll have no money. Every time he would throw a fit, get so angry, slamming doors. He even trashed our basement twice in hopes of finding hidden money but always failed.  

Today he came home unexpectedly. I didn't have school & I thought it was strange because it's a Tuesday & he's suppose to be working. He told my mom to go downstairs to talk. My mom refused because this was a very suspicious request. They went downstairs to the basement away from me & started arguing. After when they came upstairs my mom told me what had happened. Apparently, he requested a divorce & talked about splitting assets including the house. She also said while they were talking he had a knife in his hand attempting to threaten her & scare her into giving money to him. She's crying hysterically & when my 12 year old sister came home, he went to the basement & broke our lamps, flipping over shelves, just going insane. My mom, sister & I were so scared we had to call my grandma (his mom) to come over & talk to him. 

I know people might say to call the police but my sister is underage, i don't know how it'll affect her. My mom says that she's afraid child services will take her away because there's some sort of fear or violence in the house. Also my mom is afraid that even if the police arrest my dad, when he comes back home he'll be even more angrier & crazier than before. 

So please give me some advice of how to handle this, words of encouragement, anything. Thank you guys.
<bot>: Dad threatening mom with a knife because he wants money from her to gamble. Can't call police because mom is scared my 12 year old sister might be taken away by child services.