I bricked my Xperia Z - Please help topic

I was using PAC ROM on my Xperia Z since after few weeks after buying the phone, but i find PAC rom kinda slow, so I wanted to go back to stock kernel,rom. So I decidede to relock bootloader(I already did it once and went back to PAC). But this time, after relock my phone is dead, all I can do is get it into flashmode and fastboot. I am not able to flash stock firmware. I need help, please guys. I can post logs, screenshot, whatever you need.