Pontiac Repair: 6 months still broke down done everything

Question
QUESTION: this car is killing me i bought it july 4th it broke down august 11 and has not been working since. I am a single mom recently diagnosed with leukemia and unable to work so I have not been able to take it to a shop instead some good friends have been trying to help they all have are either currently mechanics or have been before and my car has everyone stumped... when it first broke down it was the intake manifold gasket, then head gasket, the the starter, then the alternater, battery, pulley tentioner, starter again, water pump for the second time, fuel filter, catalytic converter has been cleaned and loosened, and the EGR valve has been replaced now the car only starts with starter fluid (sometimes not even that) it is idling rough, misfiring cylinders 1 and 5, and has a hard time staying started but once is starts and stays running it will crack right up with no problem just still the misfires and rough idle, loss of power I mean really what else is there to replace, You can hear the fuel pump come on so I don't think it is that but I really dont know all signs pointed to the EGR valve but that didn't do anything.... the codes it is pulling is P0131-O2 oxygen sensor's voltage remained low for longer than 2 minutes
P0300-Random misfire
P1546 A/C clutch relay control circuit low
P0440- EVAP system malfunction
P0403- Exhaust gas recirculation circuit malfunction
P0405- Exhaust gas recirculation sensor a low circuit
oh yeah and gas cap and radiator cap have been replaced as well.... PLEASE HELP ME!

ANSWER: what model and year is this car?

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QUESTION: 2003 Pontiac grand am V6 3.4 L

Answer
Ok here we go. as far as it running like poop and starting hard the 440 code has nothing to do with it so that is out the window.  first thing check to make sure the a/c fuse is not blown in the under hood fuse box it may be labeled a/c BCM something like that depending on the year it's labeled differently. My bet is that fuse is blown if so unplug the a/c compressor and replace the fuse. if indeed it's blown once replaced "It should start easier" the p0300 is a big issue. #1 and #5 share nothing other then they are on the same side of the engine one side is odd cylinders the other is even. they do not share an ignition coil. if it's not misfiring on any other cylinders then those 2 then there could be a mechanical issue. has it been misfiring since the head gasket repair or before that is it constant? if it's there all the time there may be a mechanical issue here first and foremost a compression test should be performed and compare cylinders 1,3,5 and see if 1 and 5 are low compared to #3. and then go from there this could have over heated bad enough to damage a valve or a piston... with out seeing it I can't say. the egr codes should effect the starting unless the valve is stuck open or incorrect for that engine and year. HTH.