The other part of your bad experience comes from the fact that your instructor was a poor educator. Grading solely based on the instructor's interpretation of the work is the canonical teaching mistake in English. Of course, having a bad instructor will make any course a bad experience, regardless of the discipline.
It's unfortunate your experience was so terrible because I find English to be very worthwhile. I've taken some of the most advanced undergraduate CS courses in the country and they were very worthwhile. Yet AP Engish senior year in high school and one English course in college match the CS courses in terms of being worthwhile.
I think it's best to clarify what I mean by worthwhile. One worthwhile moment in Computer Science was when I finally understood Lisp macros. Another one was when I understood Turing Machines. I'd say I've had about 5 or 6 of these moments over the past few years in CS. These are moments where you feel like you understand something in a fundamentally different and higher way. English produces similar moments, but they are about the world at large instead of just a technical field. Taking one English course per semester has netted me one or two worthwhile moments a month. It's really quite something.
If you're ever given the opportunity, I urge you to give literature another try. It's difficult to find a competent teacher, but it's worth the effort.