distressing vs worrying

distressing is not a noun while worrying is a noun.

Word	Noun	Adjective	Verb	Adverb
distressing	No	Yes	No	No
worrying	Yes	Yes	No	No

As adjectives, distressing and worrying are synonyms defined as:

Other synonyms of distressing include distressful, disturbing, perturbing, troubling, worrisome.

distressing (noun)	worrying (noun)
	the act of harassing someone
	the act of moving something by repeated tugs or pushes

distressing (adjective)	worrying (adjective)
bad; unfortunate	causing distress or worry or anxiety
causing distress or worry or anxiety