No, it's totally not you.
The people who structure those books and courses LOVE the subject matter and are making it as detailed and complicated as possible. If they didn't, there would be enough of it to make a full course.
I would go to a book store with your textbooks in hand and look for alternate books that teach the same thing. The kinds I like the best are geared at teenagers. You can look at the table of contents in your books and the new books to make sure you're getting the same things. But flip through the new book and see if it seems to make more sense.
Then when you're assigned something in your class, pull out your new book and do the lesson in there first. THEN do the lesson you were assigned. Trust me, it HELPS.
I didn't go to school at all past the 2nd grade, then I got a GED after I paid a kid 10 dollars to teach me to divide. I taught myself the rest each time I had a math class. I've never had a class in grammar or lower English. The first English class I had, I was expected to submit several papers. I had no idea how to write a paper. I'm starting a doctoral program this Fall and a few years ago I ran a technical writing department. So seriously, this method can works for anyone. Go get some books geared at teenagers.