I feels pressure when breathing and seems to get tired a lot and very frequently.

I understand you are worried. Heart Disease is nothing to take lightly. Being short of breath and tiring easily can be several issues as congestive heart failure or even indicating a blocked artery. A professional is definitely what is needed. I do not understand why she must wait a month. ECG, echocardiagrams and other heart test can be done with results quite rapidly so a diagnosis can be made and the proper treatment started. Any time she has pressure, pain, radiating in the chest, and for women more on the shoulder area, she should get to the ER. Stress is a major health problem. Doctors NOW know that stress causes problem in many parts of the body and the heart can be weakened by constant stress causing blood pressure to rise and then the heart works harder. ON a good note, if properly diagnosed heart patients can live productive lives. Having a healthy diet, trying to relieve stress ( maybe talking with someone or a class of one's liking), exercise can all help a heart patient cope with their problem. Hope it all works out for her.