WHAT's IS HAPPENING TO MY NIKON DSLR? V?

My Nikon d5100 camer athat I have had for a year is doing something funny!
In the middle of the picture there's a white line and now has gotten worse and every second photo I take is black (there's a bit of colour at the bottom)
What is it! Shutter problems? Mirror?
Let me know!

It seems that you sensor has failed if you are asking about a white line.

A black line on the bottom of the image file show that you are using the incorrect shutter speed when using flash.

The maximum shutter speed on your camera is 1/200th second. Use that shutter speed or one that is longer to get rid of the black line

Agree with fhotoace. Your sensor has died and needs to be repaired. This isn't a cheap repair, so be prepared to shell out a few Benjamins.

Try using a brand new memory card and format before using. If the problem remains and it's not what Fhotoace suggests, you have no other choice but to bring the camera in for servicing.