Which One Do I Do Next

Finished my fourth book and now don't know which one to work on.  Now that may not make sense to a lot of people.  OK you stop, sit back, and take it easy for a while and recharge.  Nope, not me.
I find myself starting something before I ever finish the last one.  Now for the most part there is a reason for that.  I like to have the first chapter or two ready for when I publish a book so I can include it at the end of the book I just finished.  Great right.  Well for the reader but for me sometimes not so much.
First when I get a little hung up on a book I may sit down and write a short story or two to clear my head.  With this last book I was thinking about dong the prequel to the Blood Line series and had the first chapter done when I realized that I wasn't ready to write that one.  So what do I do?  I sat down and started the next one in the series.  OK, not a problem.  Well yes it is.  I was writing a short story and suddenly realized that I had gotten about a fourth of the way through another book and it has nothing to do with the original series.
So WindRider was born but I may change that name.  Anyway I have a good start to another book of short stories as well and the beginnings of a second book of short stories, no they can't go together, and I have someone wanting me to write a book about one of the characters from my first book of short stories.  On top of this I have a character out of my last book that may deserve a book of their own.  What do I do here?
Right now I want to give poor Emma a rest.  She's earned it.  The short story book is almost finished.  Like I said I'm about a quarter of the way through the WindRider book and it is different.  The two characters that deserve their own book we can put aside for the moment because not ready to tackle them anyway just yet.
So here's my real question.  What the hell do I do?  Come on people I need help here.  Remember the voices in my head?  Well they have gone from a choir to a cacophony of racket that may send me off to an insane asylum.  That would be OK if they give me plenty of drugs to shut everyone in my head up.  Not to mention it would be nice to get a good nights sleep.
So again anyone out there who has any suggestions please let me know.  All answers will be considered except actual murder or suicide.  Anything below that I will consider.