DH Alcohol Consumption

Sarah
Hi all!
I've been TTC since 02/14 and I've noticed that it says that a big amount of alcohol can affect sperm count and semen quality. 
My DH has a history of alcohol issues (which are currently under control) but when I mention him reducing how much he drinks so we can conceive, he thinks I am picking on him and gets angry and defensive.
He wants a baby as much as I do. What can I do to show him that just reducing a little how much he drinks will make a difference?
Thank you 😊