Well, basically, you have the following options:
1: Check whether you have bootmii installed as boot2 by checking how many times the disc drive flashes. If it flashes twice, you have bootmii as boot2. You can then use the Fully Brick, Bootmii/boot2 installed but No Nand Backup? Solution Here! guide to fix things.
2: You can ask a member with a NAND programmer whether it is possible to restore the NAND without the keys file.