I had cellulitis a month ago and was prescribed Keflex and Bactrim. I took them as directed and finished them. It was gone in about 2 weeks and now I have a large cellulitis lump again. I don t want to spend 10 days suffering from cellutlis and miserable antibiotic side effects if its just going to be back in 2 weeks again! What can I do? It s extremely painful, but I don t have a fever, chills, or nausea.