I hesitate to respond definitively because although it may seem like a sudden thing on the surface to you, rarely does someone suddenly stop being attracted to their partner. I realize that it may not be apparent to you but these things you say you called "minor" may not have been minor in the first place. So I am compelled to urge you to look deeper into this and figure out what it is that has been happening probably for a long time.

That does not excuse the fact that she's suddenly JUST NOW telling you that she's not attracted to you. Telling you that it's not "performance" and adding to that that she is attracted to other males is really quite simply a slap in the face.

I don't know what your intentions are with the marriage but at the very least if you want to figure it out before throwing in the towel, get counseling. That is, if she's willing to do so, but at this point, I don't think she'll likely want to... since she clearly sees no fault on her part.