HELP...1/2 of site disappeared

[helpme]

Suddenly my site body is not loading. The header, drop down menu and footer are there (footer is screwed up also)
I have ran the debugging tool and the file is empty. Admin is running fine. It went down when I was doing nothing, adding nothing with the database. I did delete 4 gift certificates out of the database about 2 hours ago but everything was working fine afterwards.
I also noticed that now everyone that tries to view the site in Who's Online the host is coming up:
Host: OFFICE_IP_TO_HOST_ADDRESS

squish ytush y.com

HELP PLEASE!!

[afo]

What did you change before this happened? It may be the result of an incorrectly edited file.

[helpme]

What did you change before this happened? It may be the result of an incorrectly edited file.

I haven't changed anything in a few days, the last thing I changed was some colors in the stylesheet last Wednesday or Thursday. That's what is puzzling me.

[helpme]

Update, if you have a link to a page on the site it loads but the price is 0
this happened once for me and now when I click on the link again it doesn't load again.

[helpme]

Now I see that my disk space is completely used up, it was only 3/4 an hour ago. What could be causing this?

[helpme]

Anyone have any suggestions as to what I can be taking up all the disk space?
I have 1560 mb of space and around 800 products is this enough space?