If publishing a novel is your ultimate goal, then never give up. But you might consider the benefits of expanding your writing. I've recently started writing articles for Suite 101. I'm not a prolific article writer, but I do feel that it keeps me in a sort of writing routine.
I've also been submitting stories to Woman's World magazine for a couple of years. I was so happy that they accepted a mini-mystery in May, and now have my story, Moonlight Magic, as their romance for the July 19th issue.
Will I ever have a novel published? I hope so, but until then, I'll keep working on my writing skills and expanding my writing horizons.