Please help.

There is no way to delete a discussion once you send it by yourself. In order to delete it you would have to contact mylot. Send them a message about what discussion you want deleted and why and maybe they will delete it for you. I had one back when I first started that was started by someone else on my name and it was humiliating to me. I sent my request and the next day I got a response from my lot. I explained the situation and they deleted the discussion rather quickly for me.