There's a short book called "A Mind For Numbers: How to Excel at Math and Science" that I recommend. It's about learning and studying in general, not just math and science. It's worth taking the time to read it to develop some strategies for your studying.
I also used to use flash card programs like Anki, not sure if that's still a popular one or not.
Huh interesting, I was prescribed clonodine before bed to help with restless sleep from ADHD. Might be interested in naltrexone for the alcohol?