A mom posted on my local twin moms' group's Fac.ebo.ok page last week that she was feeling overwhelmed and hoping it was just a phase that she was going through where she felt like she couldn't get anything accomplished. She has 10-month-old twins and has recently returned to work part-time as well.
I certainly cannot speak for all mothers of twins, or for all mothers who work outside the home, or for all mothers-of-twins-who-work-outside-the-home. . . but if my experience is at all a representative sample, it could be a long time before that feeling goes away. As I think I've mentioned here on a number of prior occasions, I feel like I am constantly behind.
Obviously I get SOME things accomplished, both at home and at work--if I didn't, by now, more than three years into this parenting experience, I would now be unemployed and child protective services likely would've removed our children from our care--but there are so many more things that I must leave UNDONE on a daily and weekly basis that it SEEMS that I'm not accomplishing much, or sometimes, anything. Especially when it comes to things like dishes, laundry and general tidying, which just need to be done again when you've just done them yesterday, or even earlier that same day.
I think the secret to maintaining some shred of sanity as you live through this experience is prioritizing and letting go of the notion that you will get everything done. You won't--you can't--and you just have to accept that.