[ubuntu] Messed up upgrade...HELP!

Hi,
Had my computer ruing perfect with Ubuntu 14.04LTS.

Saw the 16.04 upgrade and thought I would try it.

Was in the process of downloading it and was getting interference from another program.

Decided to just log off to stop everything.

Now I can only get a black screen with the Terminal prompt?

Can not bring up the Desktop????

Guess i buggered it good.

Just ordered a Ubuntu 14.04LTS install disk from Amazon.

Will try to reinstall when I get it???

If anyone has an idea on this, I'm all ears! Thanks!