Though the symptoms like burning sensation in chest & throat suggest towards acid reflux
...the presence of symptoms like difficulty in breathing, talking & aggravation on exertion of movement, indicate towards the possibility of heart involvement.
Investigations such as Electrocardiogram or Stress Echocardiography
can clinch the diagnosis.
So...it will be better to consult a Physician to determine the exact cause of the symptoms so that appropriate steps for management could be taken.
Wishing you a Good Health. Let me know if I need to clarify further.
Thanks & take care.