Any creative person has a time when art inspiration becomes sorely lacking. Sometimes finding inspiration is really hard and there are times when I feel so worn out and fatigued that my creativity suffers. I no longer feel the desire to draw. Art is hard work.
For a creative professional, a creative block isn't just frustrating, it is damaging.
BUT!!You have to accept that you can't please all the people all of the time, and growing a thicker skin for rejection and criticism.