agonizing vs torturing

agonizing is not a noun while torturing is a noun.

Word	Noun	Adjective	Verb	Adverb
agonizing	No	Yes	No	No
torturing	Yes	Yes	No	No

As adjectives, agonizing and torturing are synonyms defined as:

Other synonyms of agonizing include agonising, excruciating, harrowing, torturesome, torturous.

agonizing (noun)	torturing (noun)
	the deliberate, systematic, or wanton infliction of physical or mental suffering by one or more persons in an attempt to force another person to yield information or to make a confession or for any other reason

agonizing (adjective)	torturing (adjective)
extremely painful	extremely painful