What could this swollen lip be?

Well it sounds as if you are doing all of the right things in treating it at home,it could be a cold sore or it could be ,I think I would make an appt.with a Dr.and determine what is happening,a good site to look up both things on is at a href="http://www.web.mc.com" rel="nofollow"http://www.web.mc.com/a just type it in the search bar and read up on these,I hope this helps you out.