Hi Lmd, thanks for keeping us up-dated
And really good news about the referral, just try not to be worried about it, hey??

They're there to help you. And you know it might be a bit easier to be prepared, so perhaps you could write down everything about the way you've been feeling and how it's effecting you. Even keep a bit of a journal.
And if there's anything you don't know/aren't sure about when you see them, then that's OK too because you can both work through things together. Just think you're going to be leading this just as much as they are. Inc. don't be afraid to ask them questions or talk about any concerns you have about the appointment/s too!! They should be there to support you with all of that.
And btw if you're worried about walking away from there with a list of diagnosis's/things wrong with you, don't be!! For a big part they might be working with you on finding some causes (if there are any) for the way you're feeling, triggers and finding some coping skills which should start to make a bit of a difference anyway.
So try to make the most of the opportunity, yes?

Alison