LG G3 Screen Black, but everything else still working

My LG G3 screen has gone from a flickering screen to completely black, however, everything on the phone still works. The phone is still responsive, the notification light still works, the phone still has touch vibrations when I try to enter my password blindly. I looked at the water indicator (T-Mobile) in the back of the phone and 1/3 of it is pink, giving me the idea that my phone has only suffered minor water damage. What should I do? How much will it cost? Please help!