LG G2 "Fastboot mode started"

Hello guys I have flashed Lollipop zip via TWRP successfully (LG G2 D802) but now phone is only booting in "fastboot mode started". I have also tried to repair download mode by following xda forum but still same screen. LG logo appears and then fastboot mode started, Can anyone help me? Can I flash system, data, etc via fastboot? If yes please provide me the link. Thanks in advance. I am waiting eagerly for your reply. Regards, Ashar