The Saunders book is really good. Don't stress out. I was worried about the HESI (the one between the last 2 semesters, or at least that's when we took it) - enough to where I didn't study a huge amount the first time, thinking I'd use that experience as 'practice' and work much harder for the 2nd try. And I wasn't one of the best students in my class - probably more like in the middle - and I still passed it on the first try. Not by that much, but still! And some others who passed it the first time said the same thing.
Just try to study a variety of stuff - for the NCLEX I studied all of the end-of-chapter questions in the Saunders book, plus 250-300 questions on the CD, but then I ran out of time (I meant to do ALL of the questions on the CD).