Electrical problem
1998 Ford Puma Manual 94000 miles

My fuel gauge counter/dial on the dash has very recently stopped working and now is stuck showing a full tank of fuel .
i am therefore unable to read how much fuel is in the tank which i believe to be roughly 1/2 a tank.
however when i go to fill her up i can barely get any fuel in !! ?
What is wrong and how do i go about getting this rectified?
any help with this is much appreciated as i need my car to get to work for the fire service and i live 50 miles away from work..nitemare!!!!