[Q] galaxy nexus stuck in bootloader, not recognized by pc topic

hi guys,
tragedy started like that: today i decided to give miui another shot. downloaded latest miui developer rom to sd card of my galaxy nexus, rebooted into recovery and flashed miui zip and tiny kernel afterwards. stupid me i forgot to wipe cache before installing the new rom. hit reboot in cwm, which kindly told me that the new rom could make recovery unusable. here i accidentally selected the obvious wrong choice, which said "dont fix problem" or sth like that. dont know if recovery is gone now... after reboot miui was trying to boot without success (mi logo shown until you turn the phone off). so i went to fastboot by pressing volume down (my volume up is broken!). fastboot acts pretty dead: cant scroll through options by pressing volume down, cant do "normal" start by pressing power, absolute no reaction of the phone. also the phone is not recognized when connecting to pc via usb (tried the samsung original driver). phone is recognized when miui is trying to boot, but i cant send any commands via fastboot.
im thankful for any advice that lets me install a new recovery/boot into recovery/make it boot again!

fastboot mode details:
product name - tuna
variant - maguro 16gb
bootloader version - primemd04
baseband version - i9250xxlj1
carrier info - none
serial number - irrelevant
signing - production
lock state - unlocked