@Triffid14 I'm a bit late to the party, just joined and support return to work parents with my programmes.
Organising your time, taking rests, getting support and napping are great ways to get on top of your day, however, I've found through my work that energy management is the root to lasting all day long!
I'm an ex Private PA and working parent and have worked with high performers and I definitely think that working parents fall into this category! The foundation of your day, starts with your evening, how you wind down and process the day just past. Looking at what you managed to do, not what's left (reduced guilt).
Your thoughts can sometimes drain you more than the school run.
Also, look up Circadian Rhythm, it's the body's natural sleep clock. Your body works in tune with hormones, blood pressure and temperature which is influenced by sunrise and sunset. Sleeping in line with this is a magic pill. More important than nutrition.
Finally, nowadays, so many people who lead busy lives know that processed food, alcohol and white sugar needs to be cut out completely. If you're recovering from any illness, healing Mitochondria and building strength in your body is your main focus - creating and using energy wisely during the day, so you can still be there for the family at the end of the day, is key.
Hope this helps!
Btw I gave up my job, because I burnt out as a parent and thought I would use my experience to help working parents.
I've lots more tips on my Instagram.