You should be fine taking the antibiotic and the pain relief medication. There should be an information leaflet that came with each medication so do look at that too.
To help you to relieve your sinus congestion, do steam inhalations.
To do a steam inhalation, boil up a kettleful of water and pour this into a bowl taking care not to get scalded. Put some Vick or Olbas oil or any other menthol drops that you like into the hot water. Bend our head over the bowl of water and cover your head and the bowl with a towel. Breathe in the steam through your nose and out through your mouth. Do this for a duration of 10 minutes and try and do it 4 times a day. If you cannot manage 4 times a day, doing some is better than none.
This will help to loosen up the thick congestion in the sinuses, as well as in the Eustachian tube which runs from your ear to your throat.
Because there is some question with regard to the safety of consuming live yogurts whilst being on antibiotics, I suggest that to help avoid any fungal problems you can consume live yogurts when you have finished your antibiotics.
If you do find that you experience problems in your mouth and itchiness in your genitals, you can purchase antifungal medications from the pharmacy without a prescription. The pharmacist would be able to give you advice with regard to antifungal medications, but a doctor would be able to prescribe some for you.
Make sure that you drink plenty of hot fluids. Honey and lemon juice is nice and soothing.
Wishing you a speedy recovery.
Both medications are okay to take at the same time. Be aware that the antibiotic may cause you to have a metallic taste in your mouth. Increase your fluid consumption and be alert to any signs of a secondary fungal infection from the antibiotic. Yeast infections are frequently seen when taking any antibiotic, since they kill off bacteria, both good and bad. Good luck!