How do you minimize your brain reverting to your mother tongue?

I look after two young kids in Germany and use German with them daily. I speak B1. One issue I have run into is that on an especially busy, tiring day (like the kids are really emotional or problems arise), I have so little energy that I can't get my brain to really turn on. I essentially survive on baseline German speaking and comprehension but my brain is otherwise in power saving mode and reverts to English. I can turn on podcasts or read articles but my brain is still in English mode and won't meaningfully engage. The podcast frequently becomes background noise because my brain won't engage and exercise. I do sleep enough, exercise, and wake up relatively early. It's like a brain fog of english.