So I bought (on steam) n downloaded fallout 3 goty and it wouldn't start... The 'fixes' I found online didn't work (uninstall/re install, ajust some compatibility or something... none worked) ;-; pls help me it's getting annoying

Welcome to the forums

First things first check this sticky and follow the steps. That resolves most issues people have with installing the game and getting it to work.

Which videocard do you have. If it is an Intel card than you will not get it working without using a dll mod and that might cause issues for your system or hardware.

[edit]

Here is the link for the sticky

http://www.gamesas.com/topic/1465357-installing-fallout-3-with-windows-78-and-xp/