If you are comfortable on, for example, 140bpm, play stuff between 140 - 150bpm until you're comfortable on it, then 150 - 160, then 160 -170 etc etc...
By listening to your hitsounds and music, you'll hear if it's matching the music.
Or display the score meter hit error bar,
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When your hits are gradually moving to left, you're too fast. (overstreaming) When your hits are gradually moving to right, you're too slow. (understreaming)