What Causes Discomfort In Left Arm While Being Diagnosed With Angina Pectoris?

Hi. I am female 33 and i have a mother which is 65 and with angina pectoris. Since 3 years ago every time i have strong emotinal stress i feel small discomfort in my left arm. My mother told me i could be suffering from Angina and now i am becoming more stressed about that. I want to ask about how far the science came to regarding Angina and does this mean i am not capable to have long life and should i be worried to die young from hearth attack..I do not smoke i am 55 kg and 168 cm tall. trying to eat healthy...