Why is my oil gauge always going close to zero

What is your question?

I have a Park Avenue Buick 1995 and my oil gauge goes to close to zero and the red light comes on like it is about to shut off but I have to put it in neutral and then I would have to hit the gas so the gauge goes up why do I have to or what is going on with this car I say to myself I changed the oil . when I slow down it still goes close to zero but I do not know why when I get a oil change the gauge still goes down to 0 after going a few miles like I was going to work it still goes to close to the zero and the red lights start to flicker.

What makes this problem better or worse?

what seems to make the problem better or worse

How long has your 1995 Buick Park Avenue had this problem?

this problem been going on for about a few months