Citizens advice bureau, so confused to what to do....help

So i had my PIP form and thought it would be a good idea to have help from the CAB to fill the form in etc so i had an appointment with them but was 2 weeks away, so in the meantime i scanned the internet for advice about filling in the form . The good advice i found was to fill in a diary that covered 1 week stating how i cope with my disability etc and a letter from my partner who cares for me on a day to day basis. I thought this was a good idea and gives the assessors detailed information about how i cope. ( i suffer from chronic nerve tissue pain all over body and facet joint pain in my lower back) i can barely walk some days.
On the day of the appointment with CAB i had a 7 day diary, and  a letter from my partner ( carer )  I showed the diary to the CAB lady , she said " a complete waste of time doing a diary or letters etc , the PIP assessors don't look at them " i was gobsmacked , she went on to say " i wouldn't put them with the PIP form , it may go against you" i felt a little down beat to say the least but anyway she started to fill the form in, it was unbelievable , she literally filled it in herself, she hardly asked me any questions . It must have taken her 15 minutes to fill it in. 

She said she will send the form off to them but the form has so little detail, just a sentence here and there. The lady said she has got 25 years experience in filling in these forms and said they just want to see how you cope with your problem concise and to the point , not page after page of whats happening to you , they just won't read it . I sort of know where shes coming from but do you guys agree ?