1996 chevrolet cavalier

My 96 chevy cavalier has 200000 miles on it. It has a hard time starting I have to push on the gas to start it and hope the battery doesnt die. When running its rough misfiring bad and smells like GAS so bad from everywhere. Also only 3 cylinders work and its supposed to have 4 working. Im going through so much gas its crazy. When im going uphill the car loses power and im only able to gi maybe 30 mph. Can anyone help?