How do you find the energy to keep up with the toddler with the whole newborn sleep deprivation/so exhausted you can barely function/why won't they just sleep thing?

If I go to full term my oldest will just be 2. I have a feeling this one may be early as well. My oldest was a challenge like anyone going from no kids to one. I have a fit bit that tracks sleep and I remember looking at the record and there being days where I didn't get more than an hour sleep at a time and if I got four in 24hours is was a good day. How do I do that again with a very active toddler? Help please!