self-collected vs self-possessed

self-collected and self-possessed both are adjectives.

Word	Noun	Adjective	Verb	Adverb
self-collected	No	Yes	No	No
self-possessed	No	Yes	No	No

As adjectives, self-collected and self-possessed are synonyms defined as:

Other synonyms of self-collected include collected, equanimous, poised, self-contained.

self-collected (adjective)	self-possessed (adjective)
in full control of your faculties	in full control of your faculties