I want her back

hi all, i love a girl soo much, she too loves me soo much, but i told her about my past that i loved a girl in college but she never felt for me, now i never think of that old relationship, but after telling truth her behaviour changes suddenly, she told me that its difficult for me to accept but wait everything will be alright after some time, let the time go i will be alright. but, i still want her back quickly, i told her truth coz i want this relationship long lasting till death, & she never blame me in future that u r lier. but now after her changes behaviour i can't live, she always loves me hugs me but now she is feeling somthing else. i don't know what to do, but I WANT HER BACK, just like earlier, her love her care her hug, everything as it was earlier. Tell me what do i do to convience her & she told me that never talk on this subject any more otherwise i will start hating u & i dnt want to hate u....... what to do ...?