Moms, how do you do it?!!?

I'm a stay at home mom to my 18 month old and I feel burnt out! Besides being mom to my amazing little girl, I'm the cook, laundry service, housekeeper, and I run my own business from home a few hours a week. My husband helps out, but I'm constantly tired and feel over worked. Mommas, please tell me I'm not the only one feeling like this here! Those of you that are pregnant or have multiple kids, how do you keep it all together? I know in 20 years I'll look back and miss this stage of life, but right now it feels a bit like a struggle.