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.
mid-15c., "improper practice," from Old French abus (14c.), from Latin abusus "a using up" (see abuse (v.)). From 1570s as "violation, defilement" (surviving in self-abuse "masturbation," if at all). In reference to drugs by 1961. Modern use in reference to unwanted sexual activity is from late 20c. Earlier in Middle English was abusion "wicked act or practice, shameful thing, violation of decency" (early 14c.), "an insult" (mid-14c.), from Old French abusion, from Latin abusio.
<a href="https://www.etymonline.com/word/self-abuse">Etymology of self-abuse by etymonline</a>
Harper, D. (n.d.). Etymology of self-abuse. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/self-abuse