Do you have the LG bootlogo coming up, if so try this:
(Something similar happened to mine, and I hope this will help.)\
Turn off phone, then when off, hold down power and volume down button until it reaches the LG logo and then release and hold it down again, if that doesn't work, when just hold it down until you see a screen that says something like: Hard reset/ factory reset. For me it took me to my recovery screen, where I just flashed a older ROM onto it, and you should be fine. I then later flashed a recovery file. I hope this helps, and if you need it any clearer, just reply
Also from reading this, try flashing another ROM, if you have one present on the device, which will then allow you to boot-up then restore.