You just need a good rest.
Kyūyō ga hitsuyōna n desu yo.
rest; break; recreation
indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and
necessary; needed; essential; indispensable; necessity; need; requirement
yes; yeah; uh huh; negative verb ending used in informal speech (abbr. of negative verb ending "nu"); abbr. of particle "no"; abbr. of particle "ni" (used especially when it precedes the verb "naru")
indicates certainty, emphasis, contempt, request, etc.; used when calling out to someone; used to catch one's breath or get someone's attention; yo!