“Short term memory loss?”

I have something that happens to me about 2 to 3 times a year, and when it does it is frightening, disorienting, and takes at least several days to fully recover from with little to no memory of what happened during the first several hours of this experience. It begins, usually when I am asleep, or semiconscious, with a smell, and the smell is very pervasive and very strong, almost citrus like, but I'm never able to put my finger on what the exact smell is. This overwhelming smell becomes my overwhelming thought, because I can't put my finger on exactly what that smell is.

But, and herein lies the reason for this submission, when I do return to consciousness, or wake up, I am totally disoriented, not knowing where I am, what year it is, how old I am, where I work, nothing, and it is a very scary time. I had an episode like this just yesterday morning, and was able to call my mother and my wife, but even now I don't remember those calls, and am only aware of them because they told me today that we had talked and asked me how I was, and if I was better today.

So, my question to you is, do you have any idea what this could be, or do these symptoms sound like something you have ever encountered before? I would be happy to give you more detail if you need, but I really need some help to try and prevent this from happening again.

Thank you very much for your help. I hope to hear from you soon.