We all hit plateaus.
Times when we feel we're stuck in a rut, just playing the same old stuff without ever improving.
I got out of my last one, a few years ago, by expanding my repertoire, I learned to slap and started playing genres I'd never considered before. Youtube tutorials were a huge help.
As others have said, most of us have a tendency to play down our ability, especially to ourselves.
Don't get despondent, cliched as it sounds, sometimes it's more useful to focus on the positives.