I'm sorry for what you are going through and understand. While I post a lot of pictures there are quilts I haven't shown because of the potential for rip offs.
Every now and then I start going off on the lack of privacy protections most of us have on the internet. Not the optional types of browser protections and virus protections that should definitely be used. But the basic rights of privacy and ownership issues. People do not understand -- the internet is not free it is entirely funded by businesses trying to buy and sell information, specifically about each of us. Despite the good/altruistic intentions of "knowledge" it is purely greed that funds our clicks. This is why I do monetarily support sites I believe in, just like I used to buy magazine subscriptions.
For forums, there are reasons why you can't go back and delete your own posts -- because they are now part of the board and the boards history. Earlier in the internet there would be "flame wars" and people would act disgracefully and then delete the evidence. Most forums now, including this one, have the ability to edit/delete (except by moderation staff) removed after a few moments.