Honestly, pumping is more draining than most people realise, your body is literally producing milk every 3-4 hours, which takes real energy, and that's on top of the sleep deprivation and stress of caring for a newborn. The tiredness makes total sense because your body is working hard hormonally and physically even when you're just sitting there hooked up to the machine. A mum I know who exclusively pumped for months said it's a level of exhaustion that's hard to explain to people who haven't done it, you never fully rest between sessions. That said, it's worth weighing whether the schedule is sustainable for you, because some mums push through and find a rhythm, while others find the relentless timing leads to burnout or even clogged ducts from missed pumps. Make sure you're eating enough, staying hydrated, and not being too hard on yourself, fed baby, whatever the method, is what matters most.