Three quick pieces of context: I had a binge-drinking problem originally; that transitioned into a "4-6 330ml cans ~5 nights a week" - like you; and a cannabis problem.
I snapped one night when I got thoroughly smashed on a first meeting with someone (bad first impression). I got a shrink. I now have _two_ shrinks (one for diagnosed depression - Dysthymia - shrink's diagnosis, not mine, and one for general substance abuse). I've relapsed. I've missed my meds. It's hard. I keep restarting. I keep going. It's getting better. It's getting easier.
I came around to the realisation that if I stopped one problem, I relapsed on the other (stop drinking, more weed; vice-versa). I was going to have to stop both (it's freaking _hard_ after a 10-year habit). But I also had to acknowledge why I was drinking/smoking: social anxiety, stress, feeling like I "deserved" a reward for a long day, a little bit of something like "impostor syndrome" - but most often? Sheer, absolute, boredom when left alone for too long
It takes a whole-life effort for me: socialising in non-drinking environments. A better diet. More exercise (suck at that one). Medication for withdrawal. Meds for energy (stimulants) to keep me functioning. Sleep (incredibly important). My girlfriend (without whom I think I would be doomed). My managers at work (they know, and we have regular, personal-oriented catchups). My friends.
And I couldn't do any of this without the professional support, the support of my friends, and my work colleagues. The "first step is admitting you have a problem" annoys the hell out of me (so trite, so "easy"). But it's true. The second step is getting help. And it was scary at first (I'm admitting I can't do it myself, I'm a failure for not fixing it myself, etc.) But it was the right call.
A final note on the "high-functioning" part: apparently alcoholism is defined in things like the DSM as "when drinking becomes a problem - when it impacts work, family, or relationships". Mine didn't (much). But I wanted to a) stop it before it got to that point, and b) improve myself - like you said with the running, I am much better able to handle stress, to function in my development role, and to maintain relationships without only ever bonding while smashed.
That may/may not help :D But I appreciate what it's like to be at the "first stage" of acknowledging this. You wonder "do I have a problem?", "Is it _really_ that bad?". It's scary. But I would suggest that quite possibly, life can be significantly better by taking control of it. In ways I never would have thought of when I started my own journey.