Hi Nightowl , i'm glad you came here to seek help with your drinking problem .
In my personal experience and seeing first hand what happens with others your situation will progress downwards . It will get to the stage where she WILL know exactly whats going on and she may or may not stick around . You seem a nice sensible chap and I think you want to do the right thing and my advice is to come clean with your other half and explain your worries and that you are seeking help . You are still very young and NOW is the time to get this drinking fixed out be very honest with yourself . Ask yourself what would you do if she was gone for say 8 weeks at a time ? what would your drinking pattern be ?
I wish you well .