ここがひどく痛みます。

here (place physically close to the speaker, place pointed by the speaker while explaining); this place; these last (followed by a duration noun and a past sentence: time period before the present time of the speaker); these next ... (followed by a duration noun and a non past sentence: time period after the present time of the speaker); the next ...

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

cruel; heartless; hard; harsh; severe; violent; intense; strong; heavy; extreme; very bad; terrible; awful; excessive; exorbitant; unreasonable; outrageous; unfair; unjust

to hurt; to feel a pain; to be injured; to be spoiled (e.g. food)