Cuthbert scored two tries at the Millennium Stadium on Saturday as Wales successfully defended their crown while also denying the visitors the Grand Slam.
"We worked a heck of a lot over the last few weeks and it worked out well," the 22-year-old told BBC Sport. "We couldn't ask for anything better.
"We've worked so hard these last few weeks and we didn't want to let go of that trophy."
Saturday's victory over England was Wales's biggest ever winning margin against their rivals.