I was testing a portion of new code in a loop, a lot really, as I was just creating it there were a lot of commened stuff, so when I tries to comment the new code it was being an ass, so I just cut it ready to ctrl + z back.
Alas I forgot to put it back, and saved project and closed.
Yes, you're probably screwed. Consider using source code version control in the future. As a last ditch effort, you can check your autorecovery backup files for the project. It depends on your OS, but the folder is under your documents. For example, on my Windows 7 machine it's:
C:\Users\jdaughtry\Documents\Visual Studio 2010\Backup Files
I wouldn't get your hopes up if I were you though.
Suzie if you have windows 7 go into the folder that holds the files for your project. Right click on a blank space and go to properties. in the properties page go to the previous version tab. It should have a list of different versions if you have volume shadow copy turned on.
I think you've just learnt an important lesson. Always remember to paste what you want to save from the paste buffer, especially if it's a large amount of program code.
I find that opening a simple text editor and pasting text temporarily to it can be useful.
I must admit I had difficulty in following your question in the forum. Is English your first language?