Hey Bethany, I had something very similar happen to my
chickens foot, and here's the link to the
thread about it with pictures:
https://permies.com/t/71013#593594
In my meager 4 years of raising chickens, one thing I've learned about chicken ailments is to do nothing and let the chicken heal on it's own. This advice is not appropriate for all chicken problems or illnesses, but it's worked for me in my few situations where something isn't right with one of my birds, especially limping. Every single time I have a bird come up limping, I do nothing and just let the bird heal on its own, and so far this has worked in the half a dozen or so times I've had a limping bird. The swollen foot in the link above had me really worried, as it got worse and worse then looked terrible. Now that chickens foot looks fine, and in fact I can't figure out which one of my three welsummers originally had that swollen foot.
Best of luck to you and I hope your chicken turns out ok. Hollar if I can help with any other questions :)