1998 GMC ENVOY Engine And Engine Coolingenginegasoline Problems

I WAS DRIVING ALONG AT HIGHWAY SPEEDS WHEN MY 1998 GMC ENVOY WITH 43162 MILES STOPPED ACCELERATING. WHEN I STEPPED HARDER ON THE GAS, THE ENGINE WOULD NOT REV AND POWER BEGAN TO RUN OUT FROM THE ENGINE. THE MOTOR STALLED AND YET THE ELECTRICITY WAS STILL ON IN THE CAR. I BEGAN TO LOSE BRAKING POWER AND STEERING BECAME HARDER. I WAS ABLE TO PULL OFF THE ROAD, TURN OFF AND TURN THE CAR BACK ON AGAIN. BUT THE CAR STALLED AGAIN AND AGAIN, FIVE (5) TIMES IN SIX (6) MILES. THIS HAPPENED SEVERAL YEARS BACK, AND HAS CONTINUED TO HAPPEN INTERMITTENLY. I ALWAYS THOUGHT IT HAPPENED WHEN I GOT BELOW 1/4 OF A TANK OF GAS, BUT TONIGHT I WAS AT HALF A TANK. THE ONLY THING I NOTICED WAS THE OOIL PRESSURE GAGUE WAS AT SLIGHTLY RIGHT OF MIDDLE, LIKE AROUND 60 I THINK, WHICH HAPPENS ONLY...