I'll make this short and brief:

I was working on my own personal mod, for my house. It was going fine and when I left to go get a drink, everything in my house was "gone". I mean, under the cell view window it showed all the stuff I had in my house, but when I looked in the render window, all I could see was my door marker, and northmarker. I tried Right Click > View on an item, and it took me to the item, but I still couldn't see it. Anybody ever have this problem?

hmmm and have you tried to Restart CS? and did you remember to tick the mod as active file, if you have loaded it?

When I open the data screen, I tick the box beside Oblivion, and as soon as I start, I save it so I have an idea on what to focus on. I tried restarting, nothing worked.

You have to scroll down the list of .esps under Oblivion.esm. When you find the mod that you made tick the box beside it also, and click once on the Set to Active File button and then Loaf.