1995 Chevy Camaro oil gauge

I had a mobile mechanic change our oil pressure sensor today, because when we started the car the oil leak from the bottom really bad and the low oil light came on. We have put in 3 bottles of 10w40 oil into the car and the light is off but the oil gauge is flucuating between 0 and the midline. Is this normal? And can I drive it safely to a shop approx. 10 miles from my house? The mechanic said dont drive it because the engine could seize but our experience with him was horrible, so I needed to get a second opinion.
Thanks