Oh, well it's not very different from how you normally feel. Our perception of reality changes all the time to a greater or lesser degree. Like when you're depressed, you don't see things as they actually are but through the warped reality of depression. Food won't taste good anymore, or you can't see the beauty of nature, or you can't remember what being happy feels like.

I'd argue that we almost never experience reality as it is. Things are filtered through our feelings and judgement and assumptions without our conscious input. The reason psychedelics can be useful for people with PTSD or depression is because it forces a shift in our perception.