Yes, definitely learn the formulas, rather than thinking chord by chord.
Melodies you can also think of scale degrees.

Listen, listen and listen again to the originals. Sing and play along.

I like to listen to songs I’m learn when I take my daily walks. Sometimes I’ll listen to the same song for an hour.

I use the the Yamaha Chord Tracker App on my
phone and loop small phrases over and over , sing and play along. Sometimes slow it down.

Try to pre plan your shows and focus your practice time on the tunes you’re most likely to play at your gig.

Yes, it’s a lot of work! But who said it would be easy being a musician?!?