I have various experiences of group therapy, both in ED (inpatient) and BPD (community recovery support), including CBT, DBT and others.
I think that you have to remember that all therapy is hard and can be really triggering, but ultimately, you hopefully will get something positive from it, whether learning from others or others are insigtful in helping you with your own direct issues. To get the most out of gripu therapy though, you have to engage, accept it will hurt and listen to others. If you have anything specific to ask, I will do my best to answer.