How to work on a startup when your motivation runs out

In most cases, positive motivation drives a person starting a new business. When that positive motivation runs out, there are two possible scenarios. When you run out of strength, either physically or mentally, you need to work less. When I need motivation, I remove all the tasks from my schedule when deep immersion and reflection are needed. I also cancel all meetings. I leave only purely mechanical tasks that I have been doing for years. I force myself to complete these tasks and then relax in the most suitable way.