So exhausted

I have 2 kids under 3 and I’m a stay at home mom but also work from home part time. I am beyond drained. I feel like Im running a marathon everyday. Every once in a while I break down and just feel so defeated. My partner works a lot but even when he is home he’s tired and doesn’t help out much. I don’t even know how to feel refreshed again. Any other moms feeling drained? Have any advice?