I've found that I often put unnecessary stress on myself to make decision now that don't actually need to be made until later... or ever. When we have decisions to make about what we're going to do and when we're going to do it, it makes sense to first ask if we should be doing it at all.
If we would take every task we have throughout our day and honestly answer the question "Why am I doing this?" before we did it, our to-do lists would probably get a lot shorter. And our productivity level would be much higher.
When you start your Monday, start with asking why you are doing the things you do. If you don't have a good answer, maybe you should re-arrange your schedule.
Ask the question "why?" But more importantly, answer it.