I just graduated with a degree in the hard sciences this spring (I actually don't want to specify out of privacy concerns simply because it's a relatively small field, lol). I know exactly what you're going through, though; even the courses within my major were painstaking, for the most part.
I've always been a very unmotivated student, and have generally hated and avoided studying/homework. In high school, I told myself, "it'll change once I get to college and start taking courses in what I like." Not so. Then throughout undergrad, my new excuse was, "I'm only miserable because I have all these gen-ed's distracting me from my real classes." Now I'm starting grad school in the fall, and let's face it... I'm still going to hate my classes, even though they'll all be within my major - something I've been passionate about since I was a young kid. I guess it's partially the rigid structure and system of evaluations (a.k.a., tests) that suck the fun out of everything, and partially that most math and science professors are very research-minded, and as a result are so focused on abstract theory that the applications get neglected when they teach.
FWIW, I absolutely loathe chemistry too. Took AP Chem in HS, and I still consider it the most revolting class I've ever dealt with, even after completing my undergrad. Fortunately, my field is far more focused on physics, which I at least find tolerable.