Replacement screens are available at Aliexpress - mislabeled as LCD screens - and there's a thread
here that discusses buying and replacing a H2O screen from them.
But it's also worthwhile to first post a pic here (within mobileread dimensions or as an attachment) to get others here to verify that it is a breakage. It does sound like it though.
Good luck!
ETA: the thread dicusses the H2O screens, not sure if the HD is the same but Aliexpress advertise both.