I have had this experience. But I would not say that everyone is not real. That is not how I would put it. Things/people/etc exist... but the way they seem to exist while in a dual state of awareness is very different from the way they seem to exist in the nondual state of awareness.

In the nondual/oneness state of awareness, the separations between people and objects that normally seemed so real your whole life suddenly seem like an illusion. The separation is what doesn't seem real anymore. We are all different parts, POVs, sets of memories, and etc. of the same being. That one being has consciousness. The individuals that are part of it have consciousness and individual POVs, but their consciousness is part of the consciousness of the one being we are all a part of. Individuals can change or expand their awareness until they experience that one being consciousness and then retain some memory of the experience. And then they can go on with their lives as individuals with individual POVs, but with the memory that the world/reality is not really as it seems to be. Generally, this is a positive thing that helps people to cope with life's difficulties and discover more insights and etc.

During the experience itself, most people find it feels very blissful. Many feel that this oneness is full of a feeling that seems like a unique kind of love. At least, of all the human feelings that we can look to for comparison, the feeling that we know of as "love" comes the closest. But it is not precisely the same thing, because it is all encompassing. During this awareness of being one with everything and awareness of an all encompassing love within this everything, that includes the stuff that in a "normal" dual state of awareness is considered bad, very bad, evil, and etc. It doesn't mean that the individual now loves things that are generally considered horribly evil. It just means that this is a different kind of love. You can still be able to recognise after the experience that some things are very unhealthy/immoral from a human perspective and respond to them accordingly.