Well because of this, instead of acting like she was a goddess and treating her that way, I unintentionally made her feel bad about herself.
I would suggest to you Kate that NEITHER ONE of these extremes is healthy. Treating them like "goddesses" or "princesses" can actually cause feelings of entitlement, and it usually accompanies a failure by the husband to set effective boundaries as well.
Your wife sounds like she has an issue with serial infidelity. Has she ever sought counseling for this, to see why she turns to others to have that need filled? Without some good counseling, and effective boundary-setting on your part, you're never going to be able to just "Nice Guy" her back into a healthy marriage with you. Either that or she was just AWFULLY young when you two got together, and she's just never had a chance to be HERSELF, outside of her relationship with you, and she's rebelling. Either way, you're probably going to have to "let her go" before you'll ever really have her back again, in my opinion.