Advice is hard to give when you are speaking generally; not to a specific person on a specific issue. It's bold to say you should do this to achieve that; especially with little to no nuance.
I think that C.J. Chivlers falls into the generality trap when talking about scheduling time to avoid anxiety:
Sometimes you don’t have the agency to control all of your time. Again, this is not a calendar problem. Your calendar is just reflecting the truth of your agency – fix that.
If you don't have the time in the day to do what you want to do then you need to fix that is a great general idea. But, the specifics of that can vary greatly from person to person and situation to situation. There is no one way to fix that. There might not be a way to fix that.
But, the idea, the spark, that the advice springs from is a basic one: If you're not happy then change something.
Great advice in general. If you can use it.