using an LED TV as a monitor

[mussafry]

Hello,
I just bought a 32" Samsung LED TV (3d) to use as my new computer monitor. I'm having some problems:

My computer has become really slow and laggy with the monitor
The image just isn't as sharp at all. Like when searching on goolge i cant see the text clearly that under the search titles.
Running on a 1920x1080 resolution just makes the screen too big for the monitor (like it doesnt fit)

My specs are:

Core i7 2600K sandy Bridge
GTX 570
8GB ram

Im pretty sure its not my PC. Am i just using a really slow monitor of some sort? Or do i need to install some sort of drivers for this to work? My computer just feels really slow and laggy.

This is the TV i bought:
http://www.samsung.com/us/video/tvs/UN32D6000SFXZA
Here's a print screen of my... screen?
http://imageshack.us/f/11/2tv.png/

Thanks.