my car started riding very high in the back and it wont come down, it never done this before what should i do to correct this problem[]

 

There are a few things that could be the cause.
A faulty or out of adjustment ride height sensor, and a stuck exhaust solenoid are the two that come to mind.
I don't see enough of these to walk you through the diag, but a visual inspection of the ride height sensors would be first on my list.
Make sure the little arm is still attached and that the bracket it hooks to isn't bent or damaged.

Hope this somewhat helps.