Backed up Pressure from gas tank and car turns over but won't start .

Started with having to replace alternator. Then got a new battery and all the sudden it started smelling like rotten eggs. Got new battery. Very next day car dies and batteries fully charged car turns over but does not start if you spray starting fluid in it does kind of start but doesn't stay running the fuel pump itself when you take the tube off the gas is comes out and when you turn the key over it comes out even more I followed the two to the engine and nothing is coming out what is my problem please help