worrying vs distressful

worrying is a noun but distressful is not a noun.

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

As adjectives, worrying and distressful are synonyms defined as:

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

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

worrying (adjective)	distressful (adjective)
causing distress or worry or anxiety	causing distress or worry or anxiety