I agree with guitarmans whole post.
I had to learn that what I do and how I feel are two different things, and if I am being blamed for something, its really up to me to see that I did my best with a tough situation.
Being smeared is one of the hardest things to navigate when you are in it. Over time in hindsight its easier to see that the smearers had an agenda. 2 years after a smear campaign here is what I learned:
Smearing is done to regain control in a dysfunctional group. It "works" in the short term because it runs the smeared person out. Over time the people left in the group are smearers and their enablers. New members tend to believe they can avoid the smearers. The group is never really stable and healthy but with new people coming in regularly, the smearing cycles keep going. The smearer usually works hard to ensure no one runs them out of the group. Usually by being aggressive, or passive aggressive.
Healthy groups address the smearing and unhealthy groups let the smearing continue.
I also learned that the inaction by a few folks can enable a whole lot of drama by a smearer who wants to feel in control. Sometimes healthy people are there too in the group, but they are so busy with their tasks that the smearing continues without their knowledge.
If we put ourselves in the shoes of someone who is manipulative, all they need is to have access to someone to manipulate, and be in a group where there are no consequences to them for their behaviours (ie no one holds them accountable). Inaction by others is a form of enabling.
None of this is safe for anyone but the smeared feels the helplessness, shame, guilt or anger that others don't seem to be feeling. I think you show a lot of courage by wanting to apply positive mental strategies to your unfortunate experience with this group. You might have been excited about the potential for this group to be a place where good things could happen, and there is a lot of anger and grief when we realize we can't enjoy our membership in a group we wanted to belong to.
When we make the decision to walk away from a group with a smear campaign, it is very painful. The positive mental strategies come from reminding yourself of the courage it took for you to see the smearing for what it is. This was your gut and brain working together telling you that you are strong and you can get through this. ❤