Please help me!

I have a 92 pontiac bonneville v6 3800. yesturday i was drving the car and ran perfect, and now for some reason the oil gauge is almost in the red, i put oil in it and its still doing it. when i rev it, it goes back to normal. And when i come to a stop the check gauges light comes on and it beeps like crazy and dies. Also their is a squeaking noise comming under the hood. I thought it was my altenator but i dont think it is now. Im not leaking any fluids or anything. Does anyone know what this might be??

Sounds a lot like you have spun a Rod bearing... These engines had some issues with the #1 Main bearing, as well as the #1 cam bearing... Usually when we see these taken apart the faces of the #1 bearings are stripped off causing low oil pressure... When this happens it does not vote well for the rest of the engine..

How many miles are on the 3800?