Gwen Stefani's new song, titled "Used to Love You" is a heartbreaking ballad full of anguish from a broken heart. When she debuted the song on television on "The Ellen DeGeneres Show" on Monday, her simple performance on the dimly-lit stage made everyone feel their hearts break.

Ellen introduced Stefani by saying, "Two weeks ago my friend played me her new song in her bathroom and it was incredible. Last week, she showed me the music video for the song and I was blown away."

According to Ryan Seacrest website, the song was said to be inspired by Stefani's failed relationship with Gavin Rossdale, who had been her husband for 13 years until they announced their divorce in August, citing irreconcilable differences.

The song's lyrics said, "I thought I was the best thing that ever happened to you/I thought you loved me the most/I don't know why I cry/But I think it's cause I remembered for the first time/Since I hated you/That I used to love you."

Heartbreaking as it was, it was for the better, at least, according to a Hollywood Life source, who shared, "Gwen is very, very happy that the divorce is going as civil as possible. It was heartbreaking and is still heartbreaking going through this whole process, but the fact that Gavin has been very adult in settling everything between the two and really been a man about it has been very therapeutic for Gwen's healing."

The source went on, "She looks at this easy divorce with little drama being the best possible scenario to finally move on with her life."

The Daily Mail noted that it is most likely that Gwen and Gavin will share custody of their three children: Nine-year-old Kingston, seven-year-old Zuma, and one-year-old Apollo. The agreement also provided that the former couple will be equal in guardianship, although Gavin may have to take the three more often than the No Doubt singer, provided she has her hectic touring schedule to attend to.

They also didn't sign a prenup before tying the knot, but in order to reach a quicker settlement, it is thought that Gavin has decided to take less than 50% of his entitled share in their community property. If everything runs smoothly, Gwen and Gavin's divorce will be finalized by the end of the year.

Listen to Gwen's new song below, do you think "Used to Love You" written with Gavin specifically in mind, or is that too much of a Taylor Swift move for the No Doubt singer?