I've been keeping an adapted "bullet journal" for many years now.
I find it very helpful for when I feel overwhelmed with tasks - one thing I use it for is to "brain dump" a long - often VERY LONG - list of all the things I'm trying to remember on my mental "to do" list.
I've realized I feel very overwhelmed once my list gets too large - things that I've temporarily forgotten come back into memory, and each time that happens I freak out a little bit. I worry that I'll forget it at the crucial moment that I need to remember to do it. This keeps the hamster wheel in my brain turning - really busy, but going nowhere useful.
The "brain dump" list helps me feel like there is a record somewhere I can go back to, so important things won't get forgotten when they need to be remembered.
I also use this to schedule my days - a separate page for the things I have planned for each day like appointments - and also things from the big list that I need/want to do that day.
Check out this article for some interesting ideas about bullet journals, and how they might help you - https://getpocket.com/explore/item/the-life-changing-magic-of-bullet-journaling
I like what it says - there's no "right way" to bullet journal - do what works for you.
I don't really find the monthly calendar idea that useful - I still use Google for that. I also moved the index to the back of the book, so I don't have to worry about leaving enough pages in the index section at the front of the book.
If your "to do" list is overwhelming you, and you'd like to be more organized, give this a try! All you need is a blank notebook and something to write with, and you're ready to get started.