2004 Chevy Silverado dies when foot is off of gas

Hello, my name is Brian Sisk. I need help because
I'm having trouble pin pointing the exact problem
with my truck. When I first started having problems
it wouldn't start at all. I took my battery to have it
recharged and it started right up! However when I
drive it now it dies if I take my foot off the gas.
When it dies it makes an odd noise. Kindve like a
vrrrrrrrrrn. It almost sounds electronical but again
I'm not sure. I don't know if its a fuel pump, battery,
or alternater problem. One of the main reasons i
think it may be the battery is because I took the
battery to be tested and they said it was fine.
However they said the battery was "all boogered
up" and the posts were hard to get in. Any words of
wisdom and advice would be greatly appreciated. I
need money very bad and I can't get to work.