You can't go back and edit/delete posts yourself after one hour. After that you would have to contact the administrators. I don't have anything to do with that.
You've got to understand that if people start asking the admistrators to delete entire threads then everyone else's posts are deleted too. I'm not sure that is a reasonable request to ask that other people's posts get deleted because someone found out you are posting here.
You might do better asking for a screen name change for the reasons you listed. I don't know, just a thought. God bless.
I am not a dr. My statements are based on years of experience and related education. Consult with the professional of your choice regarding matters of concern.