The confusion is in the understanding of Ego, for even the second definition is a necessity to experience.
The sense of self worth is your conscious mind, and in the same token should one dissolve their sense of self worth then they would be left empty of self worth and therefore would be quite cold to the external experience. Sounds fairly nihilistic, really.
I absolutely understand that the English lexicon is extremely fluid, but what people are referring to with ego is egoism.
e·go·ism
ˈēɡōˌizəm
noun
another term for egotism.
PHILOSOPHY
an ethical theory that treats self-interest as the foundation of morality.
noun: egoism
e·go·tism
ˈēɡəˌtizəm
noun
noun: egotism
the practice of talking and thinking about oneself excessively because of an undue sense of self-importance.
"in his arrogance and egotism, he underestimated Jill"
synonyms: self-centeredness, egomania, egocentricity, self-interest, selfishness, self-seeking, self-serving, self-regard, self-love, narcissism, self-admiration, vanity, conceit, self-importance; boastfulness
"Darla's egotism will always thwart her chances for a lasting relationship"