Can Taking Cephlexin And Sudefed Be Safe For Sinus And Congestion?

I have a sinus infection. Been to the dr. who prescribed cephlex. Have been on this for 6 days. Throat no longer as sore. Major drainage.. I am using Sudefed for this. Still very congested and not sleeping well. I have no fever, but major chills. Having some sweating at night also. I am female, 60, in good health.