As a dyslexic student, actually getting in the content for revision was quite difficult. My ability to read well and for a long time is weak. Every time I revise for every year's exams I prefer a different technique, it seems! However, I did make it through to the end of a degree, getting a 2:1 (B equivalent) in Physics. Doing well on exams is possible.
As a rule, I generally try and keep revision to be in bite size chunks but over a long period of time, with the option to do something more interesting when I find myself really unable to focus. It can be frustrating for others when I deviate but it sounds like you really empathise, which is fantastic.
There's a method to make sure that enough time is spent actually revising and procrastinating called the Pomodoro Technique. It could be worth trying, at least! It involves intervals of work and breaks which has been effective for many of my peers. A better explanation: www.lifehack.org/articles/productivity/the-pomodoro-technique-is-it-right-for-you.html
Blocking distracting websites for set periods of time helps significantly. The first 20 minutes of work can be fiddly without social media but then the craving disappears. Tool available: getcoldturkey.com/
Different colour paper and pens makes a nice difference. Being able to pick a different colour for different topics within a subject or even a different colour paper for each module can be enough fun to keep focused.
If possible, arrange some group studying. Peer groups offer a nice contrast to sitting with a book and reading it.
Water - keep hydrated!
With regards to the content:
- Flashcards are not that useful to read but the act of writing does help to absorb the learning. Sticking flashcards up somewhere helps - in an exam, the thought of "oh, that definition was next to the fruit bowl. I can picture it! I can remember the definition as a result!" Worked for me. The more obscure, the better.
- Doing is learning. Just the act of writing 20 equations 5 times each got me through tons of exams. Not a great method for understanding but when this close to exams, cramming can make a big difference.
- Stick up bitesize pieces of information in different places. e.g. inside a kitchen cabinet, on the back door of the toilet door, etc. You could even give a different post-it for every meal eaten or car journey. Not all learning has to be done at the desk.
- Take advantage of youtube. Videos up to 2 minutes long recommended.
- Exam technique is huge. Make sure every past paper and answer sheet has been downloaded and practised at least once. Highlight when questions repeat themselves over the years. Patterns will appear and different exams give slightly different definitions, adding depth to understanding.
- Rewards. The promise of something after each exam is a great driver. Even giving out one sweet per question answered can be enough of a motivation to keep going.
Hopefully one of these is of some help. Good luck!