The liver is a pretty tough organ, you can destroy 90% of it and be OK, and it is good at bouncing back after being beaten up by booze. Not so things like hearts and brains, possibility of permanent damage to those organs should worry you more.
It's not easy to get your gamma gt raised in a healthy liver. In the days when nobody cared about who would pay for these things, we would get our ggt levels tested after a week of a heavy drinking rubgy tour, and none of us could get above "normal". Irresponsible youth
So I would say you are drinking more than you admit to. That's common, in fact 99% of patients lie about their drinking and smoking habits. As a rule, we would double what was admitted, and still be short.
Give up the booze for a couple of months. This will let you know what your LFTs are when your liver has had a chance to rest. It will also let you know if you can do it