Yes, I do think a dog can feel betrayed. Maybe not in the exact same way we do, but I think they feel emotions.
I don't think dogs have a concept of being betrayed. They definitely know what they like, and they know if they're not getting it.
They can be thrown off, yes. Dogs are creatures of habit and routine, but can also adapt to change, some easier than others. But try to maintain routine for you and pups sake.
It's important for a dog to have on-going bonding, sharing, and affection with its human companion (I hate saying "owner")
They do think, but they don't think like we do.
They don't blame, or judge. They will hang on in there.
But they are so much happier when their social needs are met.