2000 Honda Accord CAR ISN'T SHIFTING GEAR

Transmission problem
2000 Honda Accord 4 cyl Four Wheel Drive Automatic

LAST WEEK WHILE TRAVELING TO AUGUSTA GEORGIA MY CAR WAS WORKING FINE. I HAD NO PROBLEMS AT ALL. WHEN I REACHED MY DESTINATION MY CAR BEGAN TO JERK AS IF IT WAS ABOUT TO SHUT OFF. I TOOK MY CAR TO GOODYEAR AND THE OIL AND TIMING BELT WAS REPLACED HOWVER MY CAR CONTINUED TO JERK AND DID NOT PICK UP SPEED. I THEN TOOK MY CAR BACK TO GOODYEAR AND WAS TOLD BY ONE OF THE MECHANICS WHO DROVE AROUND THE CORNER WITH ME THAT SOMETHING MUST BE WRONG WITH THE TRANSMISSION AND I SHOULD TAKE IT TO THE TRANSMISSION REPAIR SHOP. MY TRANSMISSION OIL NEEDS TO BE CHANGED BECAUSE ITS BLACK AND IT SHOULD BE BLOOD SHOT RED SO I KNOW I NEED TO GET IT FLUSHED. IM THINKING THAT THE PROBLEM COULD BE MINOR AND IT COULD ALSO BE THE STRAINER. I DON'T WANT TO BE TAKEN ADVANTAGE OF WHEN I TAKE IT TO THE SHOP AND WITH THE DETAILS I HAVE GIVEN YOU I HOPE YOU CAN HELP.