I think every player has these feelings very once awhile. Personally I think the guitar is like your voice. You can refine your expression and vocabulary as you grow and age but it’s important not to get too discouraged because what is really important is what you have to say not that you say it perfectly. It is too easy to get weighed down in details and forget that creating art is the goal – which to me means expressing yourself in the purest way possible. And since there is only one you you are already the best at that. Yes you can improve and refine your expression but don’t forget to use what you already have to create and express yourself now.