I'm in middle leadership in secondary and it is hard at the moment. I think (as will be the case for all workplaces) it's the extra routines we are following, the covering for colleagues self isolating, the setting of work for pupils self isolating and ensuring it's done and they are up to speed with everything that makes it feel harder. In addition to trying to do the normal things we need to like develop the curriculum, continue to develop teaching and learning etc.
I am in a supportive school but I was totally exhausted when we finished for half term on Fri. It took until yesterday for me to feel vaguely human again! I know my team were also exhausted.
For me, I am trying to focus on the positives of each day, however small. In the last week for instance, a Y11 boy rolled up a piece of paper at break and was using it as a trumpet - it made me laugh and that made my day! I sometimes write the positives in the back of my diary to look back on when I am struggling. I mentioned it to my NQT and he is now doing the same 
I was also reminded in the last week how much some kids really value us as the constant in their lives -never underestimate the difference that makes!