YES, you are rooted. Before you fool around with your phone too much, turn it off, then hold Volume Down and the Power button. choose the recovery option, use volume up and down to higlight the option and press power to select. Use one of the rooting guides on here and start with the section that tells you how to BACK UP/NANDROID RECOVERY your system
EDIT: DonB has at least 1 guide on how to make a back up of your system and how to use that recovery in case you mess your handset up