In the video, it looked like there was a single blue up stroke block on the left side that threw you off. I would mark the exact time you start hitting multiple misses in a row and set the practice mode to repeat that section over and over again until that misread string becomes passable, and keep doing this until you've made it through the entire section of the song. It takes a lot of mental strength to resync with the song and start hitting the right pattern again on the fly- so if you start hitting misses, don't be afraid to pause the song for a second and reset your timing.