"able to supply one's own needs, capable of fulfilling one's own desires without aid of others," 1580s, from self- + sufficient. Related: Self-sufficiently. Self-sufficing (1680s) is properly "sufficient for oneself."
word forming element indicating "oneself," also "automatic," from Old English use of self (pron.) in compounds, such as selfbana "suicide," selflice "self-love, pride, vanity, egotism," selfwill "free will." Middle English had self-witte "one's own knowledge and intelligence" (early 15c.).
OED counts 13 such compounds in Old English. Middle English Compendium lists four, counting the self-will group as a whole. It re-emerges as a living word-forming element mid-16c., "probably to a great extent by imitation or reminiscence of Greek compounds in (auto-)," and formed a great many words in the pamphlet disputes of the 17c.
early 14c., from Old French soficient "satisfactory," or directly from Latin sufficientem (nominative sufficiens) "adequate," present participle of sufficere "to supply as a substitute," from sub "up to" (see sub-) + combining form of facere "to make, to do" (from PIE root *dhe- "to set, put").
"inherent fitness for all ends and purposes and independence of others," 1620s, originally also an attribute of God (translating Greek autakreia); see self + sufficiency. Of mortals, "ability to supply one's own needs," it is implied by 1580s (compare self-sufficient). Sometimes formerly also "an overweening opinion of one's talent or worth" (1690s).
<a href="https://www.etymonline.com/word/self-sufficient">Etymology of self-sufficient by etymonline</a>
Harper, D. (n.d.). Etymology of self-sufficient. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/self-sufficient