For me, despite that I could clearly hear the differences, my problem was identifying the frequencies. Easy to hear if it's a boost or a cut but the only way that I found in order to learn how to identify the freq was to practice training for some time until I had the most difficult frequencies for me memorized, and then tried the test again.
I had no problem with the very low or high freq, but the rest of the band sure needs some intensive training.
I think I must have spent 1 to 2 hours before succeeding at this test, so don't give up, and my advice is practice training until you have memorized the less obvious frequencies (for me it was principally 1, 2 4 and 8kHz).
Don't know if that makes sense... sorry for my poor english...
It makes perfect sense and may even have contributed to me finally getting my Golden Ears!
Not being English speaking myself I can’t judge your English, but anyway it looks impeccable to me.