In addition to @strongbow's answer to retrieving your data, it sounds like the screen is broken. To avoid buying another phone, I've attached a guide for replacing your screen [link|https://www.youtube.com/watch?v=ci_-ldhGNdg|here|new_window=true]. I would also try to reach out to your warranty provider, or Samsung, to see if they can supply you with a replacement screen. Otherwise see if you can find a screen second hand.