I'm sorry to break this to you - you went away on a business trip and when you came home she had suddenly changed. 9 times out of 10 this happens because she cheated or at least met someone during the time you were gone. Then she needs to justify her actions by thinking up all the things that are wrong with you.
I could be wrong but statistically, I'd bet money on it. Have you checked her cell phone records? If there are a zillion text messages to one number, that's likely the affair partner, whether she has actually slept with them or just having an emotional affair.
