Yes. I'd've scarcely believed it possible till I lived (just barely) through a really bad one that long.
Thing #1: Stay safe. Seriously.

Interestingly enough, I'd charted pretty regularly till then. All I have to show for that time is a pile of tiny scraps of paper, mostly illegible, missing dates, and written in every direction, going around corners and filling every space. Clumps of days from the different months were randomly jumbled together. The written information is basically useless. The state of them speaks for it.

So you won't want to use that system. There are quite a few systems out there that others can tell you about. I always just had a DIY chart one and the best I had come up with was to make a mark indicating how high and how low for the same day. Charting can be good, especially if your memory and/or concept of time are bad.