anger rover

hi new to range rovers and clueless. i have a 98 dse for the last 3months and its been gr8! up untill 4days ago when the auto box started it hard shiffed all gears it did that for about 20mls and got me home. i parked it over night and in the morning i diped the box and it was just over the full line!i went for a drive and it had 1st and 2nd gear fine 3rd was as if the cluch was sliping relly badly! no 4th and no reverse! droped the atf and 6.5lt out of it. not the 9.7 thats ment to be in it! put 9.7lt back and went for a drive.still the same but wen i got back i found she had been dumping atf out the at dipstick and from the top of the box couldnt see were from. im stumped how about you????