2003 Grand Am GT

My car is bipolar, after a 8hr shift I came to drive home but
it wouldn’t start. It always cranked and turn over, and we
could here the fuel pump so I didn’t know what it could
be. My mom & bestfriend meet me to give me a jump but
nothing. After a day & a half it sat at the train station, I
called a tow truck to tow my car home, but he mentioned
he wanted to play around with the car before loading it.
Guessing because this problem had just started. He
mentioned the day before when we tried cranking it, we
may have killed the battery so he went to the truck and
grabbed a portable charger of some sort and charged my
battery. Little over 10mins or so he attempted to start my
car after charging and everything was cool. I was able to
get gas, go to the bank, and home with no problems.
Crank & start on first start like any other time.  I eventually
came home, then left out about 1hr or 2 after to head to
Walmart, my car seemed perfectly normal, I even made it
home! After sitting for about 8hrs I came to my car to start
it and nothing!! It would crank and turn over but never
start! I eventually found a  mechanic to diagnose my car,
he mentioned my starter was new, and said it could
possibly be a faulty ignition. And the I had low fuel
pressure?? So we change the ignition, but when in the
dash he noticed my wires have been cut and not attached
back probably. They all were rapped in electrical tape
careless almost. He goes to fiddle in the dash and turns
the key and boom out of no where my car had started. I
thought it was best to drive to the gas station, to let me
car run a little so that’s what I did. After making it home,
the next morning my car yet again wouldn’t start. It’s not
my battery, starter, transmission, or even alternator. I
NEED HELP possibly failing fuel pump? Please respond!!
2003 Grand Am GT