If all you have right now is a journal try to be very specific.
My lawyer said something that stuck.
Courts want to see facts, not conclusions.
You've concluded he's a drunk. Back that up. What do I mean?
It was suggested to me to write in my journal like this. Ignore the stuff in parenthesis. I'm just making it easy to see how I may have written something to how I write it now.
She was drunk last night.(Conclusion)
(Facts)She finished off the already opened bottle of Layer Cake wine which was at 50% full. Then she drank an entire bottle of GnarlyHead in 30 minutes before diner. It was only 5:30. She was visibly drunk, did not make diner and wasn't willing to give her son a bath. After I made diner for everyone, cleaned the kitchen and gave my boy a bath and put him to bed, I retired to my mancave. When I returned to our room at roughly 9pm, the wife was unable to form words, couldn't stand and ultimately passed out.
or
My wife was hammered last night.(Conclusion)
(Facts) The stash she keeps in the closet had half a 1.75 liter of Grey Goose Vodka in it yesterday. I checked tonight and it was empty.
or
The Bottle of Vodka I found in the laundry room was marked at 25% full this morning at 6am. When I got home from kung fu classes at 9am, it was roughly 75% full. After further inspection, it was water.
See what I'm doing? Times. Amounts. Details. Facts.
You can bet your ass that he's not keeping a journal and when pressed for data, he can't give any. The courts know this. It's not their first rodeo.
Cameras and voice recording devices are admissible in court, per my location and attorney's advise.
Don't let the fact that all you have is a journal stop you from moving forward with your plan. There are ways to do it.