Sweet Molly,
You just had a baby. Your body is still finding balance after pregnancy and birth. Having one baby is exhausting. You have THREE, and you're breastfeeding and caring for a newborn.
It WILL get different. You will be able to zoom around and *play* with your little ones. Right now though, you need to take it easy and try to be kind to yourself.
What I know of you is your kindness, and your compassion. I know you also like to laugh and have a sharp sense of humor. For me, my daughter's infancy was hard because I didn't get to experience myself as a whole woman. I was arms deep in Motherhood...only. But that transitioned. I have complete faith that you will be able to feel more of your whole complex (sexy, playful, creative, ____) womanhood. It's not gone, it's just resting while you tend to your newest family member.
Big hugs. I think you are amazing. And cool ;-)
ETA: XINE has a point...he's got more energy...and there's a biologic AND domestic reason. It was the same in my house too for a year. Finally, after my husband took a turn at being the stay at home parent, he stepped up and does his share (more).