Advice for Pip diary

Hi all, I'm about to start a diary to assist with my pip claim. In Nov 2023 I injured my back while moving house,this pain spreads into my legs leaving me mostly unable to walk without a walking aid, and over the course of the next year I would have occasional flare ups caused by the simplest of things which left me practically unable to move. On Oct 29th 2025,i had another flare up which, rather than last around a week like any other flare up, has continued to this day. This pain has caused me to stay of work since, and I am for the most part unable to function by myself due to the pain as I can barely move without having to rest or I risk becoming bed bound for several hours. I cannot sit, lie down or stay stood up without any pain, and I have been unable to stay stood up for longer than a couple of minutes without being in agony since this began. I do not yet have a diagnosis, or no when this will end,and so to assist me financially I am going to apply for pip, and will begin a diary to aid me, however I'm unsure of how to fill it in and what to put in it. What would you suggest?

TLDR: injured back and not sure how to fill in pip diary, any help welcomed.