It is believed to be evolution making sure that males did not just go around impregnating females everywhere, who were then left with the impossible task of collecting food and taking care of an infant alone. The feeling of love is evolution's way of making the male return with food to the family and not just go fuck every bitch he sees and then walk away to have a feast for himself.

Your heartbreak is just evolution playing a prank on ya. Did that make you feel better?