Did you buy your phone new or did you buy it from a friend/craigslist/ebay etc. The reason I ask is that it sounds like you have something like Safestrap on your phone already. Go into system recovery...after the phone boots into fastboot mode, scroll down to recovery mode and select by pressing the volume up button. You will be taken to a black screen with an Android laying on its back with a red "!" in its belly. Press both volume up and volume down keys simultaneously, that will take you to stock recovery...it takes about 10 seconds. Once in recovery scroll down do wipe data/factory reset. That should but you phone back to stock, just like it came out of the box. You will have to download and install your 3rd party apps, but you'll have a fresh start. Then you can root, choose a custom recovery and flash roms if that is what you want.