Roughly expressed; for me, music theory is like teaching a paraplegic to walk; it's not working.
Actually, here I'm trying to prove to my mother that there's a plausible reason why my brain does not support this function.
We wrote a check and I tried to understand this the day before with laptop and materials, but like the other times I did not succeed. Even people of the same age can't explain this.
Many think that I have an incredible singing voice, as my father, who did not understand any music theory, still learned to play guitar and piano by himself, without reading music.
In learning subjects - and music theory is ultimately also much to memorize - it is often either the poor or at least "not very pedagogically skilled" teacher who explains things inadequately and unattractive or processed the lack of will; most of the time one thing is related to the other. This is how I felt in history in a year: Actually, history is even a hobby of mine, but in a school year, the teacher was extremely uncomfortable and so I found learning here also difficult; I had the three with great difficulty, although I always had a good two with other teachers before and after.
I would not regard it as a shortcoming, nor talk of personal incompetence and let the whole thing just stand ----> guess: MUsik is a minor subject and not relevant to relocation; Unless you are attending a school with a musical profile. If there's a 3 or 4, that's not as bad as in other subjects.
Well, not every person can do everything equally well. There are certainly excellent music theorists who call for animal welfare when they start singing because they think an animal is cruelly mistreated.
Do not be discouraged, you can also make great music without the theory being powerful, even professional! Vangelis is only mentioned as an example.
You have to feel music with all your senses. In the theoretical part of the music, however, one learns at best only the memorization of notes. This is basically comparable to sports theory. Both are areas in which most can only achieve positive experiences through practice and thus only the remaining stimuli are completely achieved.
But you seem to be musical according to your descriptions. And you find the theoretical content so difficult because you are most likely working on your hearing and reading notes is likely to sound like a foreign language. But this is still a musical talent and your hearing the reason that you have managed to learn two instruments without notes.
With musical regards