There are only two ostomy groups in my area, both a 40 minute drive, just in different directions. I go the the Niagara Frontier group. There are about 40 members, but what surprised me was the age, no the ages of the group. We have everything from a young woman and her husband, in their twenties, to our monthly report of those who have passed away due to old age. I have found that every age group brings something new to the table and most times have experiences I've yet to have or shared their clever solutions to a current issue. That's all I've got on the age issue. Here, I have no choice, both groups have a large age range. If you live in a large metropolitan area you may have better luck in finding what you want.
Depression. I was born with Clinical Depression. Yes, true CD manifests itself when one is young. The lifesaving/mindsaving trick is to have a parent or relative who notices it early and teaches you how to deal with it. You have it for life, there is no cure and you are not crazy. Oh, my father also had it, and he taught me how deal with it. No drugs. You must 'go' with it. Cancel all appointments and social engagements, eat or don't. During a 'bout', I can lose 20 lbs, or gain 5 (loss is more likely, real CD is not appetizing). In real CD, you sleep alot, or you sit around looking at the wallpaper. The best advice my father ever gave me (he died when I was 13). No matter how black, how bad or how long remember this: it will always come to an end. He was right.
However, any depresion I've had regarding my cancer and surgery was CONDITIONAL DEPRESSION. Not innate, this too shall pass. Conditonal depression ceases when the conditions causing it go away.In my case, and that of many others, my stoma is permanent, thus the 'condition' will never go away. That doesn't mean you will be depressed forever. Luckily, conditional depression eases over time. That is what happened to me. CD never reared its head while I was sick, and I had so much support and good medical follow-up that I didn't have any sad or deppresive feelings. Until after 8 months or so. All is well, on my own, I started to focus too much on my stoma. It made me sad, 'bummed out', unhappy. I just toughed it out and started counting my blessing (this really does work) and came to the realization that I was not in a bad place.
So, any group you find will have people that have had all sorts of procedures and all manner of stoma. A great place to be listened to and to listen to all the horror stories you may never have to endure. Whatever avenue you choose, be well.