I was introduced to theory so long ago (40+ years ago) that I don't recall the difficulty. In my senior year of HS, I recall that we started with the circle of 5ths and then we taught Nashville numbering. Then the instructor had us analyzing Beethoven's 5th, so it must not have taken too long to grasp some basic understanding. We explored a lot of other musical concepts besides traditional theory, like chord inversions and harmonics - we even built a harpsichord, so we couldn't have spent too much time grinding on the basics. I'm sure there was a hurdle to get "into the game", but once you find your "aha" moment, it becomes quite logical and can even be fun.
Theory just explains why certain progressions/chords feel good (why we as humans enjoy the resolution from V to 1 for example) and certain progressions are uncomfortable and why good music benefits from creating harmonic conflict (dissonance) and then resolving that conflict in our ears. You probably already instinctively understand some theory without realizing it: Root 5 works in a lot of songs - there's a theoretical reason for that.
I think working with a teacher or even another musician who gets basic theory will help you get past the initial speed bumps. Once you "get it", you can carry on using books and other resources to continue your understanding. Don't give up! You'll thank yourself later....