Bricked phone EMERGENCY CM12.1 rom

Hello.

I wanted to flash a custom rom CM 12.1 for my M2. I forgot to update the bootloader and it said patching system image unconditionally... and it froze then. I let the battery run out and it shut down. When i try to power it up it just stays on the sony screen and i cant do anything. Its not a bootloop its just a frozen screen.