Gwen Stefani dropped by The Tonight Show on Friday night to perform her new single "Used To Love You" with a little help from The Roots. The very personal track is the latest from the celebrated singer and judge of The Voice. Digging deep, Stefani leaves it all on the stage with a raw rendition of the single about the pain of breaking up. Check the footage below to watch the full performance. Purchase "Used To Love You" via iTunes. Get more from The Tonight Show starring Jimmy Fallon via nbc.com.