The Art of Multi-Tasking

I'm a decent multi-tasker, but I've been realizing how important that ability is concerning the world of the writer.  I have at least five projects in the works at one time, and it's a mental acrobatic act just to work on them all.  I'm in the final chapters of the first draft of my second novel, writing a novella/novel, writing a short story for a specific anthology, going over edits for my first novel, and editing stories for my latest anthology.  On top of that, I submitted several short yesterday because I've been slacking off and have noticed that the rejections have heavily outweighed the acceptances lately.  Kind of depressing.  Last year I sold quite a few stories -- this year, not so much.  But, I did sell a novella and my first novel, so I'm not complaining.  I have plenty of short stories to submit, I've just had a difficult time managing so many projects and all my submissions at one time.  I suppose I'll have to come up with some sort of method to give equal time to my current projects, but I'm not sure that will work.  Sometimes stories write themselves and it is important to focus on one work if it's flowing from me with such ease.  Maybe I'm doing it right.  Not sure yet, but what I do know is that one better learn to multi-task in the writing biz.