Hey T-123,
Sometimes Facebook goes down and it's impossible to do anything. I just tried to change my status and it seems to be working.
Click "Profile" along the top banner. When that page appears, look on the left hand side to "Information". Click onto the blue "edit" box which looks like a pencil. Click "Edit Information" When that page appears click onto the "Relationship Status" bar and scroll to the one that suits you. You have to "Save" your choice with the blue tab at the bottom of the page. I hope that helps.
~S