Sienna Miller on Managing Work and Single Motherhood: 'I'd Like to Be Better'

"I'd like to be better," the actress said.

ByABC News
September 9, 2015, 12:18 PM
Sienna Miller attends the Nine by Savannah Miller for Debenhams Launch Party at The Roof Terrace, Ham Yard Hotel, Sept. 8, 2015, in London.
Sienna Miller attends the Nine by Savannah Miller for Debenhams Launch Party at The Roof Terrace, Ham Yard Hotel, Sept. 8, 2015, in London.
David M. Benett/Getty Images

— -- Sienna Miller is having one of the best -- and worst -- years of her life.

"It's been really quite overwhelming recently, just with the volume of everything going on," the 33-year-old actress explained to British Vogue's 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."

After starring in two Oscar-nominated films in 2014 -- "American Sniper" and "Foxcatcher" -- Miller followed up with two new films this year, a stint in "Cabaret" on Broadway and is scheduled to begin filming Ben Affleck's new gangster drama this fall.

On top of all that she recently split with partner Tom Sturridge and is raising their 3-year-old daughter Marlowe on her own.

Life as a single mom hasn't been easy, Miller confessed.

"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," she revealed.

"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," Miller added. "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."