You need to recognise you can’t do your best work for clients/your program/your colleagues when you’re exhausted. You just can’t. There is piles of research that shows just how unproductive we are when we’re exhausted and burnt-out. So the idea you’re adding value when you’re pulling consistent 12 hour days is a fallacy. If anyone around you makes you feel bad because you’re leaving the office at 5pm, point out that actually you’re more committed than they are because you want to produce quality work. Well … maybe don’t say that – but do remind yourself that leaving on time is an act of care for both yourself and your work.