Failed CCNA 802 today!!!

590/825
Started studying for the exam on 5th Sept. After no exposure to CCNA material for over 6 years. Do you think I left too little time to study for the exam? I was hoping to do the exam before it expired.
Used Lammle's Sybex book
Past CCNA exam papers for reference
Any ideas on what I should do, how much more time I should invest?
Unfortunate to have simulator questions which i think i flunked on badly!
Thanks!