My Macbook Pro crashes every time I change my desktop So everytime I change my background on my desktop, I go and delete the image. The next thing I almost always find is that the next time I turn my Macbook on, the whole thing freezes and I always have to safe boot my laptop.

Once I do manage to boot up again, my original background completely disappears and my desktop goes back to the "universe" background

I am getting frustrated with this. I don't know why deleting an image will cause my laptop to do this sort of thing. My Macbook isn't even a year old.

I have OS X 10.8.2

EDIT I just restarted my laptop and now it's even worst. It's quite laggy and my whole wallpaper is now just completely blank white.
If your Mac still works, I would connect a USB drive (or other) and make sure Time Machine gets a full backup before anything else goes wrong.

At that point with your files safe, you can use OS X Recovery to run Disk Utility. The first link has some very general items in case this is the first time you've heard of Recovery or Disk Utility.

As you troubleshoot this, you can either ask a follow on question or edit the question if you can rule out some things you have tried or need more specific help using / deciding which step of these tools and guides to take next.