I'm in a real fix, the tyre's flat and I haven't got a spare.
be in a fix
To be in a troublesome situation. Boy, I'm really in a fix—I accidentally made plans with two different men tonight!We're in a fix now because the hotel gave our room away!
be/get in a ˈfix
(informal) be/get in a difficult situation: I’m in a bit of a fix. Can you help me?