Hmm. Do you have an idea to start with? Characters you want to work with? Those are usually good starting points. I know the feeling on the stress, I actually have a few current ideas in-progress that I shoved aside because I just have too much stuff to fix on them before I continue.

I've also found that with characters, if I draft up profiles I can figure out better what sorts of details I should include in the actual story. At the very least, you can keep track of names and all. Format is up to you, computer document or physical notebook pages. Whatever feels most comfortable to you! :)