You should try a gradual return to work, even before the end of January. Two hours a day for a week or two then 4 hours a day. Also, plan on how to get rest breaks and how to avoid over-stimulation. Preset time off does not make sense to me. Nobody can predict when you are ready to return to work. Only trial and error will tell you.

I am not surprised you were overloaded shopping. Stores are miserable places for people with over-stimulation issues.

Your most important need is to learn what your stimulation limits are, what your triggers are and what signs of impending overload are. Your body/brain does put out signals when you are pushing your limits. You just have to listen and watch yourself.

Needing to reread a line of text is a good sign of overload. Needing to squint to focus is another. A sense that everything is starting to move too fast or slower than expected are also signs of brain fatigue. Beginning to feel disconnected from those around you is also a sign. I am sure others can add to this list.

It takes time and attention to learn these signs but it is a necessary skill to move forward with life.

My best to you.