I quit when I was fifty. Been sober three years seven months.
If you're talking about AA meetings, I never felt self conscious. And you're right, the older people there all seemed to have years of sober time. Didn't matter to me, though, I was looking for the similarities in drinking and getting sober than I was at age.
Us old drunks can still contribute in many ways. I love to see a younger person come here and admit they have a problem. Older people, too. We're all in this together and I get inspiration from young and old.