77' 4X4 1/2 TON (DO I HAVE TRANNY ISSUES?)

I DROVE MY TRUCK ONE DAY AND EVERY THING SEEMED FINE. PARK IT, JUMPPED IN IT @ 5 DAYS LATER, STARTED RIGHT UP, PUT IT IN REVERSE, STARTED TO MOVE, GAVE IT MORE THROTTLE AS I HAD TO BACK OUT AND SLIGHTLY UP A HILL (ALL ON ASPHAULT), AND MY BABY (MY TRUCK) WASN'T MOVIN AS STRONG AS SHE DID 5 DAYS EARLIER, SO I DECIDED TO GO FORWARD, PUT HER IN DRIVE & THE SAME VERY WEAK TO EVENTUALLY NO MOVEMENT AT ALL, SO I PANIC AND START GOING THROUGH ALL THE GEARS JUST INCASE ONE JUST MIGHT WORK, AND NOTHING! WHEN I AM IN PARK MY IDLE SPEED IS AT ITS NORM, WHEN I SHIFT INTO ANY OF THE OTHER GEARS THERE IS NO DROP IN THE IDLE SPEED, IT SOUNDS THE SAME AS IN PARK. DOES ANY ONE HAVE A CLUE AS TO WHAT M,IGHT OF HAPPENED? ALSO, I CHECKED THE TRAN FLUID AND MADE SURE THERE WAS ENOUGH, TRIED TO DRIVE AGAIN AND NOTHING. I ALSO DID A BASIC TRANNY SERVICE AFTER ALL THIS AND STILL NOTHING! PLEASE SOMEONE HELP!

sounds like the front pump failed