How do you manage motherhood and working?

I’m a Mum of 4, my youngest being 6… I returned to work fulltime when my youngest started school after being a stay-at-home mum for years. How do working mums find the balance!? How do you not get overwhelmed with the constant to-do list? I’m so tired when I get home!! everyone is…(we leave the house at six and are back home around 4) how do you still be a great mum, spend that quality time with the kids and just generally keep it all together without going absolutely insane