One of the two types of negative emotional energies (stress), that come at us from outside our personal boundary. The other is called, "hurt."
The first line of defense against this negative energy and a force of unhappiness, is the personal boundary itself, trying to block the stress.
Loss is a threat or loss or a real loss, and may be emotional, such as the negative, destructive threats of a bully, or it may be physical, such as an actual assault.
If loss gets into us, it negates an exactly equal amount of confidence - the feeling of having the wherewithall to resist risk, change or loss, needs met in a paternal, fatherly way. The void left by the absence of confidence, especially if the amount of loss is greater than our amount of confidence, is called, "anxiety," which can metabolize as addiction and avoidance, impulsiveness, masochism, or their derivatives, worry, regret, or guilt.