You can't achieve accessibility over night. If that's how you define success, you're setting yourself up for failure.
Instead, consistently challenge yourself to do better than you did yesterday. Prioritise small improvements. They matter more than you might think.
You can start by setting realistic, achievable goals. Maybe that's adding alt text to images. Maybe it's making sure you have proper colour contrast. Maybe you need to learn about screen readers. Even a single adjusted heading can make the world of difference in someone's day.
If you want to define success, define it against your past self.
The big picture will overwhelm you.