Can I edit or delete one of my discussions ?

I do not think members have any access to edit, delete any discussion or response or for that matter add comment. As soon as you complete the typing of matter for any of the above, you can press PREVIEW RESPONSE and that gives a option to view the matter before finally posting by pressing POST RESPONSE. May be you can inform mylot admin with a request to delete a topic (probably they may do it if there are no responses to it). Try.