replacement lcd screen on nikon 3100

my nikon d3100 was in perfect condition until the other day i decided to take new photographs of my daughter and when i turned it on. It turns on but i have this multi-colored lines across the screen like it was water damage. Just to remind you that I've never dropped it in the water and in my life.. Am i able to repair this myself? because i dont want to spend a lot just to get it repaired at a shop. i heard it costs nearly $300 ...To me that is ridiculously insane. Does bestbuy sell the lcd replacement screen? where do i have to buy them at?

thanks guys!

kate