I believe you are being over medicated. Both Moxifloxacin and Cefoprox CV are antibiotics, and there is no need to administed Cefoprox CV as Moxifloxacin is ore than enough to treat your Sinusitis. You will however need other support medications too. Have you been give those medicines?
Next Steps
If not, I would suggest you meet me with all your previous reports and prescriptions. A second opinion will clear all doubts about your health.