Fitness did it for me as well. Lifting weights, running, krav maga, all of it sucks when I'm hungover. Plus it's easy to tell that my performance suffers which devalues the time in the gym. I hate knowing that I'm sabotaging all that time I spend working my ass off. When drinking has an immediate impact it's much easier to decide not to do it.
I started out by cutting out drinking during "the week" (defined as Monday through Wednesday as Fri/Sat/Sun are obviously weekend days and everyone knows Thurs is really the true start of the weekend). As I picked up more fitness things it pushed out drinking time. I still go out and drink but now it's once a week instead of every night.
A lot of us have the privilege of working flexible hours and for me that meant getting hammered and showing up to work at 11am still a bit hungover. I now show up to work at 9 and leave by 6, and don't go out with my old drinking buddies. Likewise I don’t try to pull crazy hours because that shit stresses me out and I cope with that by drinking/recreational drug use.
I've wanted to write more about this topic but never have the courage, in part because I still drink sparingly and am not sure that makes me an authority.
Don't worry, there are a number of ex-problem drinkers that can and do practice moderation. Some can, some can't. Some need abstinence, some don't. Your experience is not abnormal.
Instead of yoga, I took up running. I found that it worked really well to alleviate stress and was a much better coping mechanism than drinking. I feel better, am less irritated, have more energy, and I no longer feel like I need to have a drink. I now get to enjoy my drinks instead of using them as a tool to not care about the things that bother me.
If, on the other hand, you are like me an you simply drink too much, I can share how I got the situation under control.
First, I threw out a lot of the liquor in the house (I kept the good whiskey that I was already saving for a special occasion). Then, I stopped going out to bars as often and, to a certain extent, avoided people I typically drank with or found ways to socialize without being around alcohol. I also took up yoga in the mornings. I like yoga, but if I drink the night before, I won't feel like waking up for it. So, I remind myself before I go out to a pub or meet friends that if I drink, I'm screwing up my routine.
That combination has helped, and it's gotten me to a place where I can go out on a Saturday night, get a nice buzz going with three or four beers over several hours, without reaching that 'fuck it' moment where I start doing shots and smoking cigarettes till dawn.