For a week or more, I tried to tell myself it would happen, I just had to stop stressing over it, but I didn't believe that. I thought I was finished. No more books. And I was supposed to send out my finished manuscript to a publisher, who would want to know what was coming next. I had nothing. I became miserable at home. (Just ask my husband.) So I started to try and write a story I loved the basic concept of, but hadn't got to grips with how it was actually going to work. It was like pulling teeth. I felt inadequate to the task. I spent a week and wrote about 3000 words. I watched a great movie and tried to think about the why it worked. I read an article that said some writers take months to formulate a new novel. At least that made me feel better.
And then I heard one line of a new song and I had it. My new story. I thrashed out a rough plot and started writing the same day. Less than a week later and I have written over 20.000 words. Ideas are coming thick and fast. I rarely quit on anything, so maybe I will get to grips with that other story in the future, but right now I'm on a roll. and I'm loving it.
I think most writers are awash with ideas, but have to force themselves to head into a second draft and get to the finishing post. That is what I love. The concept and first draft are my nemesis.
So if you find yourself in the same situation as I was, do not fret. Something will come to you.
Good luck.