From English - German Ding/FreeDict dictionary ver. 1.9-fd1:
racked /ɹˈakt/
geplagt, gequält, gemartert
"Although cancer racked his body, he was cheerful." - Obwohl der Krebs seinen Körper marterte, war er guter Dinge.
"The dog was already racked by/with the pains of old age." - Der Hund wurde bereits von Altersschmerzen geplagt.
"He was racked by/with doubts over whether his decision was right." - Er wurde von Zweifeln geplagt, ob seine Entscheidung richtig war.
see: rack sb., racking, racking pains, rack one's mind/brain