LOS ANGELES: Gwen Stefani finds performing her old songs ''upsetting''.

The 'Just a Girl' singer - who is dating Blake Shelton and has sons Kingston, 12, Zuma, nine, and four-year-old Apollo with ex-husband Gavin Rossdale - is preparing for her 25-date Las Vegas residency and she's feeling ''very anxious'' about being taken back to bad times in her life through her own back catalogue.

She said: ''When I'm in the music, the music takes me right back to those moments in my life. And some of those moments are sickening, you know what I mean? Certain memories are upsetting. That's why I say this is not just a show for me, it's my life. It's real for me and I think that's why I'm very anxious about it.''–GN

But the 48-year-old singer thinks the Vegas shows are perfect for her as she's reaching the ''end of [her] journey as a musician.

She told Closer magazine: ''I'm obviously at the end of my journey of being a musician... It's perfect for me to be able to do a Las Vegas show. It just feels like the perfect next chapter for me.''

And Gwen is always happy to share her music with the world.

She said: ''I love my music, I love the attention and I love being able to share that love with people and get that exchange. It's my gift, it's what I'm here for.''

The No Doubt frontwoman takes over from her friend Jennifer Lopez with her Planet Hollywood shows and admitted she's a big fan of the 'On the Floor' hitmaker.

She said: ''I've always looked up to Jennifer.

''Her show was incredible and she works so hard. I admire her a lot.

''She was breathtaking on stage, but when you see her up close, it's like, 'What?! It's not possible. You are so gorgeous!' ''