it wont reverse!!

i have a 91 honda accord lx (automatic) an lately when i've been changing gears from park to drive...its like i gotta pull it hard just 2 change gears. then one day when i put it in reverse it made a loud noise like it was straining or sumthin..then as i was almost done backing out from parking it just stopped reversing an now everytime i put it in reverse it jus makes that loud noise an doesnt move. sum1 told me to check the transmission fluid an i did that an still no improvement.


any ideas what it could be??