Is the heart affected by your disappointments in life connected?

For sure: In literature, music, art, cinema. Poetry, and throughout human history, they have been inextricably intertwined. Physiologically, there is probably a medical connection too but that's a bit murkier. Statistically, in populations, happier people do live longer. One can certainly die of fright ("voodoo death") due to an arrhythmia and due to takasubo's cardiomyopathy. May be true for disappointment.

Yes: Emotional ups and down will affect your heart by different ways including activating the sympathetic nervous system and others neurotransmitters that deal with your heart. Chronically may permanently affect your heart. Look for help. Friends and family, your physician, god. In my life prayer have pulled me out of many emotional problems. I will pray for you.