What's going on?

Hi Friends,I think I mentioned I sell Avon to you before, and I'm not trying to sell anything here, but the information is relevant in my problem.  I continued to keep up my status while I was getting surgery and radiation with the help of my daughter and friend.  Of course I emailed most of my customers and some ordered online, and some just waited till I was done, so I didn't have much to do.  Now that I'm home, I started trying to do it again fulltime, and I wonder if it's too much for me.  I love doing it, love my people, but I just totally screwed up an order today due to the fact that I simply can't remember what happened before.And that brings me to the point that I have been noticing that my mind is not as sharp as it was before radiation.  I've been frustrated and downright embarrassed that I am repeating myself, or missing things and forgetting things.  I feel like I am losing it!  My therapist thinks it is normal for my stress level, but I am getting scared.  I've never had this problem before, other than when I had dissasociation problems from abuse, but that was more clearly a mental health issue.  Is this a menopause thing, a stress thing, a medicine thing, a Fibromyalgia thing, or all of the above?  Or is it Alzheimers like my mother-in-law died from?  I know there is a thing that Fibro Fog known to those with Fibromyalgia, but I didn't really know what it was.  Anybody relate?Thanks!