I am sorry to disagree with everyone here. Yo DO have a problem. You have only one bookshelf and a project in mind for every piece. To me that is not a stash. A stash is fabric you got for no reason at all, that you will later use as you see fit. If you have a project in mind for every piece, they are not available for "emergencies".
The solution for your problem is to go shopping, but now for the stash. The real stash! Because you like it!