Hello I share your concern tightness in chest is a matter of concern, this could be due to heart or lung disease This can be very easily ruled out by EKG, pulmonary function test or cardiac markers. Nausea could be related to Acid peptic disease like gastritis which could be due to ingestion of antibiotics You can take anti acidity medicines like pantoprazole and antacids Meanwhile please follows these guidelines You should take steam inhalation for sinus infection Have multivitamin supplements especially vitamin C and B complex Avoid fatty fried spicy and junk food Have fresh fruits and vegetables Hope this answers your question Thanks for your question Regards