The repetitive word or phrase that gets stuck in your head or you keep saying is also known as Perseveration. Its not as rare as you think. I've had many many patients with this side effect from a brain injury.

From Wikipedia : Perseveration is the repetition of a particular response, such as a word, phrase, or gesture, despite the absence or cessation of a stimulus, usually caused by brain injury or other organic disorder.[1] If an issue has been fully explored and discussed to a point of resolution, it is not uncommon for something to trigger the reinvestigation of the matter. This can happen at any time during a conversation. This is particularly true with those who have had traumatic brain injury.

In regards to your brain fog, that most certainly happened to me off and on for 6 months or so....and i noticed it finally ended when i got my anxiety under control and started doing Healing Touch and Acupuncture. It was usually triggered by overstimulation....which for me could have been anything from driving, music being too loud, too many people talking, lights being too bright, playing poker, being out of my normal environment.

I posted about it in the beginning when it was first a major concern of mine....but quickly realized that some symptoms and side effects you just have to accept, acknowledge them for the weird things that they are, and learn to work around them. I stopped doing the activities or actions that caused them to happen and saw a huge decrease in the amount of times that they happened.

Consistency works wonders. Stick with an easy routine day to day that doesnt bring on your symptoms...you will figure out what works. But the anxiety will only make things worse off. When you start ruminating over every little symptom, that in itself will send you into a brain fog. Maybe take a few weeks off from this website too and see if the less you are talking and writing about it, the lesser your symptoms become. I also found this to help with my anxiety....to stop reading about everyone elses anxieties and focus on learning coping mechanisms and ways to handle my stress and anxiety. Sorry buddy.....i know this isnt easy.