Damn man. Sry to hear about that.
I know that telling someone to stop drinking is easier said by us than it is possible to do by you. so that is not really good advice.
You have potential to be great in the 100m, looking at the 100m flys you did, you were constant in getting average 12.7. You can definitely run 11.8s if you run now and if you train to push that I don't see why you shouldn't be able to get close to 11.2 - 11.3. But drinking may block that goal.
This year is almost over, before it is over, weigh out your options and see what you want to get rid of from your life and how you can get a better alternative. So you can enter the new year with a plan on where you want to be, who you want to be and how to get there.
I don't know what you think about attending counseling sessions or AA meetings, don't know how effective they are but I guess it helps you open up on your problems. Also may help with distraction.
I have no experience in this so I hope I have been helpful but knowing you and the work you put in day in and day out working hard for what you love, especially the grueling sport of rugby (which imo is my least favorite sport because of a bad time in high school of standing in winter cold raining with shorts in one spot while others they play and fall on the floor, I even asked the coach to quit but he said that was not an option lol), but you are a tough guy and overcoming this will not be difficult for you.
pc
EDIT: cute kid, use him as a motivation. Be the father you would have liked to have when you were a kid.