I've way less programming experience than you, but I hugely agree. I started out wanting to "learn programming", and I struggled without a task. Project Euler(maths puzzles to solve with programming) helped me learn the basics of python, but I stagnated for a few years because I didn't see any way to use what I'd learned, any ideas for projects.

Things really clicked for me once I took a bioinformatics module at uni. The average life scientist is scared of the command line, but I was suddenly faced with so many ways to practice my programming skills by pairing it with biochemistry learning. Now, I'm better at coding than the majority of people in my field, even if I'm still mediocre overall. I know enough to be able to do stuff that I want to do now though