Hang in there and find a meeting! Any meeting that you can squeeze into your schedule. In my experience, finding AA was like finding instant friends and activity-filled nights/weekends. If you have an unconventional schedule, there are likely meetings in your area that accommodate it. I was never bored or alone in my free time unless I wanted to be. You could also take a class or volunteer somewhere or use meetup, like you mentioned.
As for the beer you bought, try changing a few things around to avoid this. You could take a different route on your way home to avoid places that sell booze. Or, if it's unavoidable (which I understand because I live in a city), try buying a new wallet or even just putting something in your wallet to signify that you've made the decision to change. Anything that signifies change and causes you to pause when faced with those impulses or surprise decisions will help you stick with your plan.
If you stick with your plan, the thought of drinking will lessen so much with time that you'll rarely ever notice that beer store when you walk by it...