Should I take her back? Ladies? is she confused? (Long)?

So i was dating this girls for 3 years i treated her like queen... like no lie i was really good to her and i loved her so much. The feeling was mutual she was obsessed with me for basically the whole relationship. Then over the course of one month she changed, she stopped answering my calls and was a huuuuuuuuuuuuge ***** to me, not even her friends really new what was going on with her. She told me she didnt love me anymore but she still cared.. then she proceeded to go party her ******* face off while I was very very depressed. SO ANYWAYS now its been 8 months later and she is trying to get me back saying she made the biggest mistake of her life and is acting like her old usual self that i fell in love with... but my trust is shot. I want to take her back so badly but I have a very very looming feeling that i never had before about trusting her with my heart again. I dont know what to do.. i dont want to get my heart ripped out... that was very painfull.