Thank you all for the comments and emails. Just to give you an update, the antibiotics are working. The first antibiotic I was on did nothing, so the doctor prescribed Augmentin. With the antibiotics and a lot of draining (ew, I know) it is slowly clearing up. It still looks pretty gross, but nothing like what it was. The swelling has gone down, almost completely. Now, I just have to wait and see if this is an isolated incident, or if it comes back. If it comes back, then I have to worry about surgery. For now, I'm keeping my fingers crossed!
p.s. It's a sweat gland issue...I don't sweat under my arms, and that's apparently not very healthy!