I just broke through the wall you're talking about recently, so I can give you a pretty comprehensive answer.
Looking at your profile, you're nowhere near ready to take on full 5*. However, feel free to try some of the easier PP maps such as Triumph and Regret, or Capsaicin. What I'm assuming you're referring to as "lost when it comes to 5*+" and "can't tap fast enough" is the spam part in the middle of Capsaicin. Don't worry about that, I can barely hit it either.
For now focus on beating more and more 4* maps. Then S as many as you can. Make sure you learn a variety of patterns like Jackhammers and Long Notes because you won't be able to progress much further with just jumpstream/trill. Sometime after you can confidently S most 4* maps, you will hit a wall where you can't beat 5*.
Once you do get there, you have to stay motivated. This wall is probably the one that separates casual and serious players. The hardest thing will be staying motivated and wanting to play, as anything below 5* feels too easy while anything above 5* feels spamming (which its not, I promise). Make some friends, play fun maps, and FARM PP.
Farming PP is really looked down on in mania because it seems to be pointless, but for me it is what got me through my rut. Seeing your rank rise is really a motivation booster. You'll notice some days you do really well while others you suck. It happens a lot.
In osu!mania your physical tapping speed isn't that much of an issue until 6* and above. Most of the time its a mental block, and while most people just say to "play more", it shouldn't be monotonous practice. On those days you do really well, you'll get more confident about your reading ability and that mind block will be cleared over time.
TL;DR, play more, get lucky, and clear mental blocks.