The poorer your self-esteem and the lower your self-confidence, the more easily negative feelings can overwhelm ordinary good sense.
We are all hungry for love, acceptance and belonging. Rejection can still feel like death.
Happiness requires a balance. If you feel rejected, you need to pursue love with dignity. If you feel put down you need to restore your dignity in an attractive fashion.
Feelings can have a life of their own and you have very little direct control over them, except perhaps to make them worse.
Once upon a time, loss of love, rejection, weakness and loss of territory all meant death. Now it just feels that way.