no matter what i flash, i always got my previous rom

hi, i got this weird problem with my galaxy nexus, after i turn it on, after 10-15 second everything crash and it reboot itself.

so, the problem is, no matter what i flash, i always got that system with all my app installed, i tryed manually from adb, with toolkit, formatting data, system, cache, nothing, i always got that system with all my apps, i tried, in that 10-15 seconds, to unistall some app, but after the reboot the app is still there. i can't install a custom recovery, i can't install any other rom, please someone help me because i have no idea on what to do