I am going to be blunt.
In your post I hear a lot of excuses and explanations. Your success would have improved if::
- You attended all classes/lectures without worrying about which ones you can be excused from or if anyone looks at the slides.
- Make your cheat sheet for exams the day prior.
- Make sure you know where the exam building is the day prior.
In short, be proactive in your behaviors leading to success. There really is something to that old Boy Scout motto “be prepared!” Good luck.
Personally I think you have to accept the outcome of the grade you earned in this class.