Perhaps your group were trying to show you that they aren't judging you. I wouldn't want to react to someone opening up about a sensitive topic in case it makes them feel guilty or bad. I would want them to feel accepted
I wouldn't label what you're doing as BAD, but I think it's unhelpful behaviour and you have done well to recognise that its a problem, and to want to do something about it. It's great that you're talking about your past with a group, and I don't think it's something to be ashamed about. Maybe you could try to find out what makes you want to go to hospital and why you feel the need to go there. Whatever you gain from being in the hospital, see if you can find another, healthier way to achieve it. You could be putting a lot at risk by trying to get put in hospital.
Do you get the same experience from seeing a therapist as you do from being in a hospital?