Eating Disorders Support Group
Eating disorders are marked by an obsessive need to control the intake and/or purging of food. This community is dedicated to those struggling on the road to recovery. Join to discuss your experience with others and find support. Get advice, ask questions, and meet others who are going through similar struggles.
I don't know of any off-hand but my best advice would be to google exactly what you are looking for. Your therapist suggested OA - so maybe try "OA for people under 30?" or something like that?
There are people on this board of all ages so please feel free to post here and get support. It's a great group:)