Before I graduated from college, my aunt gave me the book, The Artist's Way, which prescribes this basic task as you've described as the foundational exercise for creativity. The suggestion given was 3 pages a day no matter what.
The content of the workbook at places doesn't totally resonate with me, but I'd say there's enough in there that it's worth trying out. It definitely asks you to confront and reflect on a lot of things that have happened in your life, so it can be uncomfortable and bring up a lot. But that's of course an important part of art making.
I'd say just try it out, it's only 12 weeks and you can always bail if it doesn't work for you!