Sorry I can't help with Femara as I am yet to start it, but I found that I have that problem anyway since menapause kicked in properly. Can't even carry on a conversation when I am tired.
I was put on minimal dose HRT and wow, the side effects cleared, back to normal again.
Breast cancer diagnosis and off HRT, back to fog and speech problems again.
Treatment side effects of surgery and chemo made it worse, as has radiation. I am going through radiation at the moment and my brain is shattered, I cannot think straight.
If it is not written down and referred to constantly, I will forget it, it is frightening.
I think it is a combination of stress and fatigue.
Perhaps talking to a cancer related psychologist could help you, they may have some relaxation strategies to help, some insights into why it is happening and how you can work on them.
My biggest fear is losing my words and conversation ability, I feel it is an essential part of who I am and I am a very organised, competent person, usually.
I will be discussing this with my psychologist at the Cancer Centre on Thursday.
I hope you find some way to get back to being you, too, Jennie