I know your pain, I had cracked my tablet's screen after a very minor bump. I have replaced its screen again, and had to do a lot of DIY modding to make the screen fit. But now the tablet's touch works a lot better than before. So I am once again a happy father of a happy tablet.
You can try to find if someone's selling a dead PB 360 here in the flea market for cheap by posting a want-to-buy thread, and use its screen on yours. And if you cant get that or if a new replacement screen costs more than a hundred bucks, you are better off getting a new reader.