Hey, Mbb15!
Keep your head up! Days with a lot of sales, days with few sales, and days with no sales are the natural ebbs and flows of the business!
However, it would be good to take a look at the files you were generating sales off of, note the size and the content, and then look at the referring sites, and you may be able to determine a fine-tuning of your uploading strategy!
Regards,
Willy!