HELP!!! LG G2 no recovery no download no fast boot

Hi so I accidentally flashed a G4 rom while trying to go back to stock and now my device won't power on. I've tried recovery and download mode but my screen just stays off. My computer detects it as QHSUSB_BULK. Someone said to download Qualcomm drivers so I did and now it just says my phone is unknown USB device. Can anyone help me? Oh and no disk drives pop up either like some others have gotten