"It's been really quite overwhelming recently, just with the volume of everything going on," the actress says

By peoplestaff225
September 08, 2015 04:00 PM

Sienna Miller is now a single mom, and she admits that juggling work and a toddler is no easy feat.

“It’s been really quite overwhelming recently, just with the volume of everything going on,” she tells Vogue UK in its October issue. “Everything is shifting. It’s actually been the s—tiest year, and amazing. It’s always yin and yang. I feel like if you’re excelling in one area, it’s hard to manage both and I do feel like the work is going really well.”

Miller, 33, and boyfriend Tom Sturridge split in July and have a 3-year-old daughter, Marlowe Ottoline.

Mario Testino/Vogue UK

“Obviously when you have a baby it’s the most incredible experience, but your life is also catapulted into this chaos and you are exhausted. I could literally get on this table and fall asleep,” the Sea of Trees actress says.

“I’d like to be better at managing things; I’d like to be more super — although we’re never going to feel it, even if we are. That’s the curse of motherhood — we just run ourselves ragged. I’m just trying to get a sense of what that guilt is. I sometimes feel like it’s a totally invented emotion. It’s strange to be punishing ourselves this way. It’s not healthy.”

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A source told PEOPLE in July that Sturridge “wanted to get married and have more children. Sienna didn’t,” the source said. “This year everything exploded with Tom in London and Sienna leading a separate life in the U.S. and [her appearance at] Cannes,” where the actress was busy in May with the high-profile role as a Cannes Film Festival jury member.

This summer she also began production on a Brad Pitt-produced film, The Lost City of Z, where she will star alongside Sturridge’s longtime friend, Robert Pattinson, and Sons of Anarchy‘s Charlie Hunnam.

Mario Testino/Vogue UK

— Sheila Cosgrove Baylis