I'm sure you have plenty more good pictures than you think. We're often pretty hard on ourselves.
This is a lovely shot with plenty of feather detail and lovely colours. Well done!
A small tip... If you're not already aware, the 55-300 (like most lenses) performs best when stopped down a little, and this is never truer than at the long end of the focal length range. Your shot was taken at 300mm, f/5.8, ISO 100. You could afford to go to f/8, ISO 200 and a similar shutter speed. That would give you sharper results with even more detail (by stopping down from wide open), and the noise performance at ISO 200 won't be significantly different from ISO 100