Oh My God! I know you hear this a lot, but DO NOT give up. First of all, if you need to improve on your writing skills get your hands on "The first five pages" and "A touch of Dash" by Noah Lukeman. He improved my writing more than any writing class ever could. Second, don't listen to those rejection letters. If you believe in yourself, there's always an audience for you--ALWAYS! For years, I was told by just about every agent in these United States that my work wasn't good enough. But when I joined Kindle, people wrote me and said how much they enjoy reading my books. I couldn't believe it.
One lady's daughter was dying of cancer, but my latest book "Cause She's a Good Girl", helped her to escape and it made her so happy that she could escape into my book and find relief for a while. Another reader called me "amazing"--me! These are the reasons you don't give up. This is what gets you inspired. Believe in yourself and keep writing, and you'll be called "amazing", too.