2000 neon stalled backing up now won't start

A week ago I had trouble w/ starting my neon. I would start it and about 30 sec. later it would stall out. Repeatedly it would do this but once I got it on the open road it would be fine. So I had a diagnostic test done and it turned out to be the camshaft sensor. I had that repaired and it was running smoothly until today. See this is the thing I got up this morning and started the neon no problem, let it warm up for about 15 min. Then I got in put the car in reverse hit the gas and it stalled, I tried to start it again and it won't kick over. Can anyone help or lead me in the right direction at least.