Give up, you are doing the Smithsonian website. Almost no school does it for its lowest average out of all the texts. Sorry but that is the sad truth.
I wouldn't say that it is impossible to get a good mark but it will be very difficult. Not trying to be mean but that's how it goes. I'll try to help you as much as I can for your related but you will need to prepare, if you want to be flexible, three related (two bare minimum)
Here are a couple, they are not about the same event but are in different mediums so it allows you to analyse the different techniques used in each medium, how they are different but are still a "representation of text".