I have silent reflux and due to that swollen vocal cords i have breathlessness on exertion all heart and lung test are normal can lpr cause breathless?

Check for VCD: LPR: laryngeal pharyngeal reflux - when gastric contents rise up into the throat, beyond just usual heartburn (GERD). Sometimes it triggers spasms of the vocal cords trying to prevent aspiration into the trachea. Normal lung tests will miss this, unless you ask for flow-volume loops. Check inspiratory flows; look for cut-offs in airflow when breathing in.