Car hesitates, then dies starts again put dies as soon as you brake

Started hesitating running off at a half tank,  been
keeping it full runs great. Today however I didn't
have time to stop at gas station and at half a tank
it studdered at light. Died while trying to park then
started again running rough. Luckily made it to
destination but then car would not start. Called
someone they put in 2 gallons. Finally got it started  
ran a little rough but died as soon as I braked
backing up. Any ideas?????  Really hoping not the
fuel pump, lol. I have replaced spark plugs at
dealer, fuel throttle regulator, new timing chain,
head gasget, new radiator w hoses, new rotors
bearings this car bleeding me dry