That really scares me. I will have to think about upgrading to these non official versions of WM. I guess I'll wait till September for the official 6.5 release. Phew. Sorry for you mate. All the best. May God fix your mobile. Miracles do happen. Don't lose hope.
try use o2 stealth updaterom if you can connect via activesync in your pc, if not copy hardreset.exe and updaterom.exe from folder updaterom utility folder in localsetting in administrator setting folder