This phrase is spelt "self-assured".
Spell it as you have done in your question but hyphenate the words so that you have self-esteem
Self esteem.
ourselves
Self conscious.
The correct spelling is" self conscious"
Me. It is a personal pronoun that means self. It is an identifier for one's self.
selves
No. Spells aren't real.
The correct spelling is "self-conscious" (focused on one's own appearance or status).
The survival instinct is spelled "self preservation".
The correct spelling is "independent" (self-sufficient).
The likely word is selfish (greedy or self-centered).