Sinusitis has symptoms like feeling pressure on forehead, sinus drainage, fatigue, poor sense to smell and taste, bad breath, sore throat, ear pain etc. You need to undergo detailed evaluation and rule out
deviated nasal
septum, blocked sinus, presence of foreign body etc.
You should take rest; drink plenty of water, salt water gargle. Antibiotics, antihistamines, cough syrup will help you but to be taken against prescription.