If you don't have energy, then you are doing too much. Pace yourself. If you think something can be delivered in 5 days, say it needs 10 days. Otherwise this is just a road to burnout and exploitation.

World will not end if project is delayed by few weeks. You get time for your own tinkering (never tinker on company stuff, even if that would improve things, unless you are shareholder).

This so much. When there’s a real urgency, you will know it (aka the whole team will be brought in). A good pace (as in not ruining your mental health) is feasible.