Interesting question. I found my identity in my mid to late 20s. I started drinking later (early 20s) but really didn't drink heavily until my 30s. My alcohol use escalated over the years. At some point it crossed over to alcoholism, I'm not sure when.
You started drinking early. Perhaps, you didn't have the chance to do it then because all your energy went into using and then into quitting. It requires as much energy to quit drinking as to be an alcoholic IMO at least for a while. I've read that drug abuse has your personality growth stunted to the age you started uncontrolled drinking. You've only been quit for a few years now. Im betting a lot of those few years you were battling with quitting and didn't have the energy for much else. Now that you don't have to battle with quitting any more I'm betting you have the energy and clear mind to find it.
The question is how though. I don't know that I did anything . I agree with a poster above. It's a process.
Also no one is stagnant, People change over the years, some more so than others. I don't think your identity stays stagnant either.