That feel when you want to collaborate with someone else on a story but you don't know anyone that you work well with

Also when nothing you create interests you for more than two days

Not sure about the first, but I can feel you on the second. It hasn't happened to me in a while though, I've been rather productive lately for some reason...

I don't know much about the first either, but I think writing while listening to certain types of music helps a lot with productivity.