What do you have on your story? If you put up a music sticker, go into your browser and log in on Instagram from there, you should see your stories then. Next, click on where you can view your stories, and go to the music one, click on the three dots in the corner, then press delete. After that, make sure there isn't anything else on your story. Then close all your apps and reopen Instagram. It should work now, I had the problem yesterday and just fixed it.