When I've writer's block I'll write something and leave it. I'll "step away" from my writing and do something totally different for an hour or three. After a while I'll go back to my writing and see if my brain has the next "instalment." If not, I'll take a "holiday" for a few days from my writing.
I learned to "listen" to my brain. When my brain "signalled" it had enough, I immediately stop my writing for the day.