I started playing organ in my early teens using sheet music. My teacher taught me music theory as well. I quit after 3 years, not sure why. Just took up keyboards again in my early 50's. I looked for contemporary christian music that I wanted to play on the internet and found only lyrics and chords. Since I heard these songs many times before, I played the melody by ear. In a few months I had accidentally taught myself to play by ear. Still need to know what the chords are though. This means YOU CAN TEACH YOURSELF TO PLAY BE EAR: put the sheet notes away and force yourself to figure it out. I will have to put the chords away to teach myself to hear the chords, but I'm sure this can be done.
Starkeeper