Why can't I edit a post anymore.

This new blogger format has me stumped after a year and three months with no posts. I can't figure out how to edit my last post and add the photo for week number one that I just finished editing. I only have 14 minutes till week one is over and I've GOT to get that photo posted...never mind trying to write something profound! Facebook won't upload the photo either....what happened while I was taking a break???? HELP anyone? ! Week 1 of Project 42