[pfarnsworth]

You pretty much nailed it on the head. Fear of Failure. Why exactly are you afraid of failing? Who are you worried about being embarrassed to? This is what you really need to work out, because who cares if you "fail", at least you tried, and the beauty with programming projects is that you learned along the way.

You need to stop worrying about it being a success, and instead concentrate on making as good a product as you can, for your own education and pride. Imagine you are going to submit this along with your next job application instead. You want to showcase your programming abilities, not in your abilities as an entrepreneur. Change the focus of WHY you are starting this project, maybe even assume that it won't be used at all except to show any potential employers what you can do.