As far as Music Theory goes, there’re a few hurdles that look utterly unsurmountable as you approach them. When I took my first theory class, I almost dropped out/failed so many times because it looked to me like I’d never understand the concepts involved. (I was one of the less bright cookies in the class who struggled with the concept of inversions)
Honestly, it’s a situation where you have to not just learn what they’re telling you, but also practice it as much as you can. I personally recommend picking up software like Aria Maestosa. not for producing, but AM is good for practicing and getting the hang of applying music theory without the use of expensive software like Sibelius, and it challenges you to get creative by being almost exclusively usable for music notation with only the most basic MIDI sounds as far as I know.