I struggle with this feeling all the time! I started playing guitar when I was 17, and I still felt like a late bloomer.

I play 4 instruments, and something I've noticed is that right before my playing gets better, it feels like I actually get worse. The more you play and the better your ear gets, the more you notice things that need improvement with your playing. Unfortunately, our musical skills don't steadily increase, sometimes we plateau and don't notice improvement for a while, but if you keep practicing every day, you'll have another "ah-ha" moment eventually.