There is a "Write" option on the left hand side list. Tab on it will lead you to a page where you can create new stories/contests. If you scroll down, you will also see "My Stories", "My Active Contest", and "My Past Contests". 
I think this story should be on your "My Active Contests" category. You can click on the contest, then click on your issue/entry, and edit it directly and press "Update".

Thank you very much!