Bad Proximity Sensor

I have a first generation SE. When I’m on a call holding the phone to my cheek, the screen doesn’t go black and I end up hitting random keys or the mute button.

I have tried every type of reset, cleaned the screen, etc. but the proximity sensor doesn’t work. I’ll have to get rid of the phone if I can’t fix this.

It’s no longer under warranty. Is the only fix to get the screen replaced?