Welcome John. I've been trying to quit for about 4 years myself. Longest period of sobriety was a year and a half, followed by my latest 2 year drinking run. Now I'm starting over again and on day 15. This time, I really truly want to quit.
I consider myself a functional alcoholic as well, and can relate. While my drinking hasn't put my job in jeopardy I have called in sick because I was hungover and. I know my work production isn't as high when I drink the night before. So at some point, if I don't stop, it will affect my job.
I too used to just drink all day on the weekends, especially during football season. I loved my Sundays of football and beer. Hated the Monday hangover and the eating bad greasy food to make myself feel better.
Don't know if I have specific advice, but if you want to quit, seek help. This site is great, and I know many people find AA very helpful as well.
We all have the power to quit. For me, I had to accept that the only thing I have control over is whether or not I drink. If I choose alcohol, then alcohol controls me.