Hi there
I actually did a pretty similar thing. I was referred to an addiction counsellor and was pretty successful at cutting down, keeping a journal. But after a few months I got really fed up, my intake started to creep up again and so enough was enough, that was last September.
Basically, alcohol still had control even though I had cut down - it was in control, not me, looking forward to my next drink. It really is simpler to think "can I drink tonight? NO!" than thinking about units/next drink.
As another poster said, I think you have to come to that conclusion yourself. To me, it sounds like you will get there. It really is easier to not to have to think about it.
Take care.