Tecomsin, from my experience at many in-person mental health support groups (Depression and Bipolar Support Alliance), the group is set to be more topic oriented than therapy. In fact, the facilitators specifically state that. That didn't mean support was not part of the group purpose. No, but support in a general sense or for issues directly related to depression, bipolar, and/or anxiety. I know your son causes you great anxiety and I understand your need for support with that, but the group I went to would not be able to solve a specific problem related to your situation with your son. Or be willing to simply hear "a venting". If you came across as complaining about anyone to a large degree, the facilitator likely should have rerouted the direction/focus a bit. I know your intentions were surely not bad, though.

As for online support groups, I've only attended one in the past. Again, the same organization as above. Online stuff adds an additional stress, I think. We're all frustrated. Anything triggering or "complaining-like" exacerbates that. Regardless, we all have our own strong opinions on various matters (i.e. parenting). Hot bed issues should be avoided. Parenting, in this sense, becomes not so different than politics or religion.

Do you have a therapist? Some conversations are best had with one.