self-sustaining vs self-sufficing

self-sustaining and self-sufficing both are adjectives.

Word	Noun	Adjective	Verb	Adverb
self-sustaining	No	Yes	No	No
self-sufficing	No	Yes	No	No

As adjectives, self-sustaining and self-sufficing are synonyms defined as:

self-sustaining and self-sufficing: able to provide for your own needs without help from others

Other synonyms of self-sustaining include self-sufficient.

self-sustaining (adjective)	self-sufficing (adjective)
able to provide for your own needs without help from others	able to provide for your own needs without help from others