This girl keeps messing with me, but I still like her? How can I get her back?

You need to move on from her because she has not gotten over any of her exes and she probably will not. So it is best if you just move on and let her be a thing of the past. There are plenty of other girls out there. So I am going to ignore the fact that you said "making me forget about her" is not an option. So you better understand that she is not ready to settle any kind of commitment with anyone at this time. She is just wasting your time. So move on and look for the right girl who will treat you better and only care about you