back from the first session - was a nervous wreck when I was driven there this morning and still very much so

I never realized how anxious I would be, I've done therapy before for different reasons.
I have a loved one with DID and we didn't really talk about much this session, it was basically an introduction and she I blanked out, feeling very su'real-ish. oy, probably not a good start to this whole thing.
but, if I may a favor, if anyone knows any good books on the subject that would probably be at a local bookie? I'm sure I only have a minor problem but it would be good to read up on because of my relationship with someone else.