When I got sober I didn't know if I was an alcoholic or not. I just knew my life was nuts, and most uncomfortable. So I went for 90 days without by going to as many meetings as I needed to go to, taking suggestions, etc., telling myself I would reevaluate after I had 90 days sober.
The fact that I went through withdrawals was a big clue. And things improved. But that's just a start.