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 15c., regulaten, "adjust by rule, method, or control," from Late Latin regulatus, past participle of regulare "to control by rule, direct," from Latin regula "rule, straight piece of wood" (from PIE root *reg- "move in a straight line," with derivatives meaning "to direct in a straight line," thus "to lead, rule").
Meaning "to govern by restriction" is from 1620s. Sense of "adjust (a clock, etc.) with reference to a standard of accuracy" is by 1660s. Related: Regulated; regulating.
<a href="https://www.etymonline.com/word/self-regulating">Etymology of self-regulating by etymonline</a>
Harper, D. (n.d.). Etymology of self-regulating. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/self-regulating