PIP assessment tomorrow - advice needed

hi,
I got an appointment with capita for Friday. I advised it didn't suit and ended up accepting one tomorrow. I suppose I want to get it over with

I am claiming on the basis of depression, I have also said in form that socialising can cause my overwhelming anxiety

where I absolutely have to socialise I use 'below the counter' help to get me through it. It effects my work and I basically don't have a social life anymore. Work is the one thing I have to do each week and that's about all I do, although I rarely complete a full week and use leave when I just cant face the day

so, assessment is 1130am tomorrow. Can you advise what to expect and if there's any materials already here that I can read?

I'm pretty stressed about the prospect and have read others talking about how upsetting the assessment can be.

what if I'm in a good mood tomorrow, does that mean I automatically fail? should I answer on the basis of my worst days? I have read the guidance that disability impact on part of the day should count as the full day and I should be able to carry out activities 'reliably'

I also want to avoid being turned down and having to appeal as a former friend works in a PIP Appeals team and I don't want him knowing my personal business. I work in DWP but not in PIP. He would be delighted to spread the word of my PIP claim. that's a separate issue to the initial assessment but my wife and I agreed we'd rather not appeal than have this scum able to spread my personal information. I had considered reporting him if this were to happen but things can be passed by word of mouth.

so I'm feeling fairly angsty and don't have much time to prep but any help is appreciated