Finding it hard to stay focused on goals when I’m tired


When I’m physically tired and exhausted I notice that it’s easy for me to lose focus and stay present with my mind.

I notice my mind goes in the direction of all the bad things that could happen and beating up on myself, and I’m overall not feeling good and optimistic.

I’d like to get to a place where I can be tired and exhausted, yet still be able to not let my mind run wild with unhelpful thoughts and be happy/content.

Is there a place I can start with when I notice that I’m feeling tired and exhausted?
Thank you.