Thanks for your feedback! I think playing this at tempo with control is simply beyond my ability at this point, so I'm not even trying, working on easier pieces. I taught myself this piece three years ago, and once I realised I actually could do it, I was very surprised, and basically stood back and realised that I should take this seriously and get a teacher because I probably had some talent. Initially, I was discouraged because everyone said it was impossible to learn piano at my age, so I was like why waste money on a teacher when you'll never be able to play well anyway?
That said, if I were to work on this piece, I would definitely approach it differently. The best idea I have heard so far is to program in wrist relaxations with octave groupings in short bursts.
P.S. – You are making GREAT progress and I don’t want to discourage you – so ignore my preaching if it is irritating! 
Not at all, and thank you! We can be our own worst critics so it's great to hear that my playing is getting better at a good pace.
Topic: Sixth Hungarian Rhapsody octave section