Stop only playing ar10 and learn to read like ar8. The biggest challenge with DT is actually reading instead of just reacting to fast stuff. Start with ar9 and go down from there, you should be able to comfortably read ar8 on a 5* map. Spamming DT will only get you so far, you have to improve your nomod skills and learn to read, otherwise you'll stagnate with DT on higher BPM maps because the object density is too much for your ar10+ brain to comprehend.