In a similar situation years ago, I was tired of playing rock tunes and just went to horn rock, Chicago, Stax & Volt/Muscle Shoals, Memphis Soul, Al Green, Curtis Mayfield, Motown, and then to Burt Bacharach, Herb Alpert, Carpenters, Wrecking Crew era music, and all sorts of adult pop from the 60's and 70's. I just got away from guitar dominated music and it helped me develop a much better ear.
These things can take years to get into. One helpful thing was that many of these songs dominated radio when I was a kid so, I knew where the music was going. All it took was adapting to (some) different chord tones and keys. All helpful and important things to know. Just go at it and have fun. It AIN'T work!
Understanding the Nashville Number System helps identify (and mentally retain) song structures.
When I'm killing time in a bar either between sets or just hangin' out, I'll listen to the overhead music and try to figure out the structure as a song plays. For Ex: "Hmmm, sounds like a 1-5-3-2, or a 1, 6, 4, 5, or a 1, 3, 2, 5", etc.
Sometimes, not having the bass or guitar nearby is the best way to learn ear training.
Maybe some of this will help.