I'm teaching in kindergarter and voice always tired

I'm teaching in kindergartens and training centers and voice always tired. 26 hours of nonstop teaching a week. From Tuesday to Sunday, only Monday is day off.
+ Every morning warm up my voice for 1 hour.
Voice recovery fast and sounds awsome if I have no work for 2 days. but during the week get worse and worse.
I'm using portable loudspeaker but and try to speak quiet. It helps but still my voice can't sound that good during singing.
How to use speaking voice maximum safely for vocal chords?
+ Every morning warm up my voice for 1 hour.
Voice recovery fast and sounds awsome if I have no work for 2 days. but during the week get worse and worse.
I'm using portable loudspeaker but and try to speak quiet. It helps but still my voice can't sound that good during singing.
How to use speaking voice maximum safely for vocal chords?
Comments
https://kentamplinvocalacademy.com/2020/06/voice-repair-heal-from-home-course/
how do you warm up your voice?
https://forum.kentamplinvocalacademy.com/discussion/6859/how-to-get-access-to-the-ktva-how-to-sing-better-than-anyone-else-student-areas-of-the-forums#latest
I have a tip that I have used for my work and I can answer it in the student area.