My XABF (ex-alcoholic boyfriend) started drinking heavily when he decided he had cancer. He didn't, he just decided that he did, because that's what he decided to believe.
At first the drinking was mostly contained.
Then it was partially contained.
Then he couldn't control when he drank, but he did control how much throughout the day, and he was constantly complaining about everyone else but saying how wonderful I was for sticking by him.
Then he couldn't control when he drank, he drank everything he had available, and he blamed it all on me, and told me what a horrible person I was because I couldn't make him stop drinking.
It got even worse after that, and eventually I hit my own bottom and left.
Alcoholism is a progressive disease, and it's very easy to get sucked into the madness, and just wonder over and over if there's something that should have been done to prevent this.
It's important to remember the 3C's:
You didn't
Cause it.
You can't
Control it.
You can't
Cure it.
Originally Posted by
SweetDina 
This alcohol abuse is the worse thing ever, second to none. It just hurts to cry everyday, to miss work because I couldn't sleep through the drinking, it just hurts. You think that if someone survived cancer they would start to enjoy life and learn from it, but unfortunately he didn't. I'm all for helping him but enough is enough and I told myself to move forward before I get resentful.
This alcohol is certainly causing a problem for YOU, which means that yes, you need to do something about it. We can't tell you what to do. We can tell you what we did. We can tell you what worked for us, and what didn't work for us - but ultimately, you need to do what you feel most comfortable doing, when you feel ready to do it.
I will say that you can't make him stop - he will only do that when he is ready, if he is ever ready.
I will say that attending Al-Anon helps - a lot. I'd recommend attending at least six meetings, some different, before deciding if this is right for you:
How to find a meeting in the US/Canada/Puerto Rico
Also, you mentioned that there is a three-year-old involved. Living in this situation will absolutely affect him, so he will need some sort of assistance as well. I am not experienced with children, but I do know that the three-year-old will need to feel he has a safe parent to go to should he need someone, and that trying to make excuses for his father (or talking badly about his father) will make matters worse.
You are in the right place. You are not alone.