Hi LB and Welcome to the forum, you might want to have a look at the following FAQ which explains where everything is
Welcome to Benefits and Work I am hoping you have time to see this before your assessment, although I know it is unlikely
We certainly have members with fibromyalgia who have applied, and been awarded, PIP but I don't know whether any of them will be on the forum this afternoon.
PIP will be awarded because the claimant scores enough points (8 for the basic award and 12 for enhanced) against the specific descriptors. Although a diagnosis helps, it is not the 'be all and end all' as people with the same diagnosis can be affected in very different ways.
What to expect from the assessment is explained towards the back of our PIP guide, if you have time to read it.
www.benefitsandwork.co.uk/help-for-claimants/pip Good luck!