Your PSP screen can be easily replaced by a reputable service center. If you are lucky and only damaged your plastic cover one can be found at Amazon or may other on-line retailers.
A Broken screen while possible to order and install yourself is better left up to a professional to ensure the functionality of your PSP for years to come. Lint and other fine particles can get under your faceplate during a screen install and can be very distracting during game play. Company’s like use static free rooms with heavy filtration to ensure damage doesn’t occur during the install of a PSP screen.