I encourage everyone who puts their work "out there" in the world to not be discouraged. Truly understand that just because one individual turns down your book, your play, your research, your song, your design, your performance, etc. doesn't mean it isn't good; if something isn't right for someone it probably isn't, but it may be perfectly good for someone else.
The above painting, Sorbet, is the only painting that didn't make it through a review in a gallery selling my work. I took it to another gallery and it sold straight away and has since been one of the most written about abstractions of mine on the web. Just remember, everything is subjective to the moment, keep doing what you love, and godspeed.