Return to stock rom when rooted already - D852

I have a LG G3 D852 that I rooted and installed TRWP on it. I modified many things on this stock lollipop rom. I want to return it back to original condition. I tried the factory reset and it works except it says "Unfortunately, home is not responding." I cant get into the home screen.

Is there a way I can flash a rom to get it back to stock?