Lg g3, started restarting randomly and now wont go past the lg logo without crashing

Hey guys
i always end up coming to the forums after i have tried to fix my phone for several hours
so far i have tried several times to revert it to stock and it seems to revert and boot, when i almost finish the setup (entering wifi, logging into google) it turns of and then attempts to reboot, it then gets to the lg logo and then crashes and so on, keeps going until the batterys flat
I have tried to install several different roms, tried another kernel, revert it to stock and it keeps happening!
Can anyone help me? I really need my phone!!!!!!