My oil pressure Decreases when I break at a stop sign/stop light How to fix it

What is your question?

Every time I drivie my automatic 1990 Ford bronco XXL full-size bronco. My oil pressure stays normal when pressing the gas pedal. but it decreases when I break at a stop sign or stop light. how do I fix it? And this is coming from college student that's been in college for only three months but before I was in college I was working on my car for a while until I went to college and then I stopped working on it

What makes this problem better or worse?

Every time I press the gas pedal estates normal but when I break it decreases to the left

How long has your 1990 Ford Bronco had this problem?

I have had this problems sense 4 months ago 4 1/2 Months