severely vs seriously

severely and seriously both are adverbs.

Word	Noun	Adjective	Verb	Adverb
severely	No	No	No	Yes
seriously	No	No	No	Yes

As adverbs, severely and seriously are synonyms defined as:

Other synonyms of severely include badly, gravely.

severely (adverb)	seriously (adverb)
to a severe or serious degree	in a serious manner
with sternness; in a severe manner	to a severe or serious degree
causing great damage or hardship