Welcome!!!!!
I got sober at the beginning of May and I turned 40 in July. So I am not 50 but I do understand the self defeating talk as I have so many friends in AA that got sober in their 20's. I got sober when I was 26, stayed sober for a couple of years and went back out for a decade. I still want to kick myself but I can not regret the past today, I have to live my life to the fullest from this day forward! I am almost 7 months sober and I could not be happier. I did it without medical intervention, on my own with the fellowship of AA and a strong relationship with a higher power today. You can do this and we are here to support you!!!!!!
Get into action! My best advice? Take a volunteer commitment as soon as possible. Offer to set up chairs, make coffee, etc. Show up to meetings 15 minutes early and stay 15 minutes after the close. You will be amazed at how quickly you feel a part of! Keep posting!