I have a severe oral biofilm infection that contains influenza, and strep strains predominantly (roughly 60%. with the influenza at 40%, plus many others not identified. Now I have a severe rash on my cheek. The dermatologist gave me omnicef, which I think is a cephalosporin. I had to quit taking rocephin, another cephalosporin, in the past because I was getting non-healing sores. What class of antibiotics should I take?