Good evening lowyat member.. i am involved in a triangle love.. the story is like this

There were a pair couple, they already engaged for 2 years, signed all the paper/document, we all worked in same company,
ok..then i fall in love to that girl, and that girl also have good feel towards me, (the time i fall in love to that girl i already know the situation), just at last december, the girl suddenly confess her love to me, and then everything get started. (means underground love)
and she told me that she want to leave her current husband/boyfriend? and then i believe on what she said, and i fork out rm 4k for her and find a lawyer firm and lawyer for her, just to help her get back her freedom. and i spent quite alot of money to her, to buy her everything..

Now everything already at halfway (in progress of getting back her status) , she staying with me for already 1 month, and i am very good to her, take care of her everything, unfortunately, on this valentine day, she got surprised from her ex husband/boyfriend at my company..and eventually, she move out from my house and move back to her ex's house..

i am so upset , what the fxxk , she told me that she decide to leave her ex due to her ex is not good to her, and then i determine to help her in everything, and end up become like this, so in this past 2 weeks, i keep on ask her to move back, and she did said she regret to move back, and i told her, just leave him and come back to me, i will take care her for everything, and i got her answer is.."i am considering" ..seem like she is dragging me more than sincere want to solve the problem..and her ex already start to held the wedding party and hear that they will go to taiwan for wedding photo shoot in Mid of March..

...and i admit...i very love her, i feel like lost everything when she move out..become no motivation, even my colleagues and supervisor also notice that.

so my question is:

am i did something wrong that cause her to move back??

is it still worth to wait her?do i still have a chance? i set a deadline to myself, which is before they go for photo shoot. If by that time, she still do not have any response, what should i do??
i already pay out everything for her, but why end up i get this kind of pay back?    

Kindly please advise..thanks for reading my story and sorry for bad English.

*we are all just 25 years old

*edit : each time i ask her still love me, she will answered she still love and miss me, is she trying to entertain me or i still really have chance?

i feel like i am lost