I struggled with that for a while. In a lot of ways, I'm still struggling, because my writing has yet to fully 'recover' from that period. By that I mean I don't produce at nearly the rate I used to, but I'm still determined to get back to that pace.

After my first book failed to sell, I couldn't write anything. Anything I could force myself to finish was sub-par, not up to my standards, and the heart just wasn't there. After I couldn't spit out a half-decent book, my agent left me. It was a huge low point in my career. For years after that I didn't write a thing. I focused on other areas in my life and convinced myself that I didn't need to be a writer. Since it caused more pain than enjoyment at that point, it was easy to reconcile that maybe this failure was for the best. And for a while it was okay. But then more and more I became aware of this emptiness in my life. Without writing, there was a hole in my life that nothing else could fill. It was then I decided that no matter how many times I fall on my face, this is something I have to do.

So I'd suggest taking a step back. Write short stories or non-stressful pieces if you want, but take a step back and ask yourself, "Can I live without this?" Not in a mean way, but I found that question really put things into perspective for me. Maybe I could live without publishing, but not without writing, and so it made me realize all the other crap was worth it. Sometimes when we can't write it's because we've gotten stuck in our own heads. Publishing can sometimes be demoralizing to the creative process. Maybe you just need some space from publishing and the pressures that come with it.

At the very least, I know you've got more books in you.