I had the same issues. Use FreeGee and got the recovery bootloop. From there I tried everything. After a reboot got nothing. Just like the rest. I sent my phone out for JTAG and a week later it was back in my hands fully operational. The guy who did it was named Joe over at brickedmyphone (dot) com. not trying to advertise for them or anything. But for $50 I was able to get my phone out and back in 7 days fully operational. It wasnt a bad price either. I contacted Joe up front asking questions on if JTAG would work and he thought so as well. If JTAG doesnt take, he will refund the price minus shipping costs back. So really you got nothing to lose.
I can say that I was happy. He got my phone and JTAG it the same day. Sent me pics of it operational and everything. I was able to verify it was mine by the IMEI in one of the pics he sent. He sent it out that day and I would have had it back in 6 days but there was a Sunday involved.
LG Optimus G Pro Stock Rooted
Phone Bricked trying to FreeGee it.
Unbricked by JTAG