GL,
You wrote,[...I think maybe the administrator there doesn't know how much he hurts people there by blocking them...].
My overiding concern here is you, my friend. As to if he knows or not, I still want you to know that you did not do anything {bad}. If the reason was about a post that may have had issues about suicide or self-harm, then those type of posts could have been deleted.and an email sent to you that posts involving self-harm are not permitted to be posted.
That way, you could have remained unexpelled from the community and recieved support that you came there for. You have come here for support and I am glad to have the opportunity to help you understand that you have not done something bad by posting on a mental-health forum. It goes without saying that people on a mental-health forum will be those that are not in their best state to even understand the rules of others because they could be preoccupied with their distress and that is whyy they are there , to get support.
In your case,if the offending post was about self-harm, the post could have been deleted and a message sent to you to do an internet search to locate groups that specialize in the helping of those contemplating self-harm. It is not bad to write about contemplating self-harm in a mental health community,although the forum may have rules that prohibit those type of posts. And those forums can easily email you on how to find a forum that can give you support in relation to that without expelling you from the community.
You are not bad, and I hope that you can get support from here to help you understand that. The post in question may be not permitted by that forum, but you are not bad for posting it because it was posted on a mental-health forum and deserve no condemnation, for self-harm is part of the struggle for those in depression.
Lou