To be honest, I find even this difficult. Told you I could be beyond hope!
In particular I have two problems with “keeping rythm with the body” (be it nodding, tapping fingers, tapping feet, swaying from one side to the other):
I don’t mark the beats but I slowly begin to follow the melody or the subdivisions (like for instance I find myself marking each eight, spelling out the smallest unit of subdivision so that I am always effectively “counting” in 4)
And/or
I find myself slowly drifting from the music, so that instead of latching my internal clock on the music, I “listen too much to my body motions” and I drift out of time.
So my current best hope is to always use the metronome and try to stay as much on time as possible. Which is giving me some (small) improvements but is also boring (hence I would like to spice it up with drum loops but I found out that I am unable to decode them in my ears)
You could start with using grooveful as a metronome, ie: just simple metronome functionality but with drum noises so you get used to listening for the cues.
The most common and basic start would just be kick on odd beats and snare on even. Next up would be kick on all four and snare on even; otherwise known as “four on the floor.” Throw in a high hat on each eighth note and you have a really common drum pattern.
Not sure if you’ve done the B2B course, but Josh talks about drums quite a bit and has a great groove exercise.
From some of what you’ve said, definitely sounds like you need to start with the basic beats suggested. I’m still very new to bass listening to simple drum only beats is helping me
