I am of the mind that if you think you might have a drinking problem, you probably do. That being said, I can certainly relate to the feeling of not really wanting to quit, thinking I could moderate, white knuckling through "moderation" and being miserable.
It's a lot easier to just not do it. You save so much money, and since you're into "fitness" (I'm athletic myself), you will see big returns in the form of better physical performance, better body image, better skin -- everything. People were randomly telling me how great I looked and asking what had changed within two weeks of quitting. I'd just shrug, say thanks, and say I was on a diet or whatever, but it felt really good.
Committing yourself to 30 days is a good idea, but you might want to consider that everything you love to do drunk, you can do sober without the hangovers and shame and all the other crap.