So I've been sober for a couple years now and I've met many others in various stages of their own recovery, and what you're describing sounds extremely familiar

So I've been sober for a couple years now and I've met many others in various stages of their own recovery, and what you're describing sounds extremely familiar. Every person's addiction is unique, but self-isolation is a common trait among alcoholics (and probably people with addictions in general). One of the best exercises we did in recovery was list out as a group what our priorities in life were. It was things like "my partner", "my career", "my health", "finances & having money to live comfortably", "having friends", etc. And when we were done and were happy with our list, the instructor went up and wrote alcohol at the very top. When you're deep in addiction, even if you know it's not rational, even if it's not what you want, the addiction is your top priority. If you have free time, that's how you spend it first; when you have money, it's the first thing you budget for; when you're doing other things, it's what you think about. And for a lot of people, self-isolation makes it that much easier to feed that addiction.