self vs somebody

self and somebody both are nouns.

Word	Noun	Adjective	Verb	Adverb
self	Yes	Yes	No	No
somebody	Yes	No	No	No

As nouns, somebody is a hypernym of self; that is, somebody is a word with a broader meaning than self:

self: a person considered as a unique individual
somebody: a human being; person, singular, assertive existential pronoun; pronoun, person, singular; quantifier: assertive existential

Other hypernyms of self include individual, mortal, person, someone, soul.

self (noun)	somebody (noun)
your consciousness of your own identity	a human being; person, singular, assertive existential pronoun; pronoun, person, singular; quantifier: assertive existential
a person considered as a unique individual

self (adjective)	somebody (adjective)
(used as a combining form) relating to--of or by or to or from or for--the self