What Can I Do to Win My Fiance's Heart Back?

It sounds to me like your fiance wants what she can't have and doesn't want what she can (and does have). I say this because as soon as she thought you were slipping away from her, she was all over you, whereas when she is sure of your love and devotion, she wants nothing to do with you. Why would someone want someone when she thinks is slipping away (or who is actually unavailable).

The answer to this question stems back to a specific childhood wound: having been raised by an unavailable parent. I suspect that your girlfriend yearned to be loved by a parent who was too unavailable to meet her need. This type of early experience primes her to seek a lover or husband who is unavailable, partly because this is a familiar scenario and partly in order to heal the early wound by replaying it with a lover or spouse who is as ungiving as her parent was. Choosing someone like the parent who let her down makes it feel like she is actually returning to childhood and doing it over again. If she can pull this off, it will feel like she won her unavailable parent's love.

This explains why you appeal to her when you unavailable--she sees a chance to replay her struggle and strive for her happy ending; when you are available, you hold little interest for her. The other possible cause for her disinterest in you is unresolved abandonment issues. On a daily basis she may pull away from you as a cover for her own fear of being dropped by you. If she holds back, then she imagines that your leaving won't hurt as much. Then when you seem to actually be pulling away, her terror of losing you, of being abandoned, rises up and she chases you and draws you back to her and voila, her abandonment fear is temporarily eased but the conflict isn't resolved and she soons pulls away again.

No matter which of these two dynamics is causing her to pull away from you when you want her, then to come in close when she thinks you're leaving her, you're still in a big mess. The only way you are ever going to keep this woman interested is by keeping her off permanently off balance, nervous that you might take a hike at any point.If she is on edge, she will need to pull in closer to you.

Keep in mind that you are playing a game that may keep her distancing behaviors in check, but it won't solve the underlying issues that cause her to pull away from you.