I note that you are obese
and your symptoms suggest either anxiety
or heart disease
.If your problems occur on walking or climbing few stairs or wakes you from sleep,consider heart problem.If your problem occurs only when you encounter a terrible situation then could be because of anxiety.Your weight too contributes to the problem.So you can contact your physician who will examine and measure your Blood pressure,Body mass index
,heart ,pulse rate etc and may suggest a ECG.He may refer you to a cardiologist if recquired and advice you on cutting down weight.
wish you good luck