You have problems that everyone has, no one plays 99%-100% perfect combos every play on every map. Everyone gets fluke misses. Playing lower AR doesn't do much to fix consistency. To fix consistency you just have to play a lot of maps and understand why you make a mistake and instead of retrying the same map over and over just move on to the next map. As you play a variety of maps you will be able to predict notes more easily and read patterns faster because people generally use the same mapping methods. The only problem in this are those few maps with the odd patterns, but that usually just takes a retry or two to read and memorize. Just try not to stress too much or you'll psyche yourself out and miss because you're thinking about missing. So as an example, if you're having trouble with fullscreen jumps then play different maps with lots of fullscreen jumps instead of one single map. Streams work the same way, grinding one map does nothing but make you memorize the map without teaching you anything.
If you're missing consistently on every map with every play you just need to play more or tweak some settings to be more comfortable.
Also play the slider start and slider end as regular notes, understand why they are both there and try not to hold both keys (only one is needed)