HI Catra,
Brain fog is so frustrating. I had it really bad when my pain was at it's worst and remember being horrified to be unable to remember things I'd known for years, like the combo to the back gate or God forbid my sister's married name at one point! I am sorry you're having to deal with that.
If you haven't had vitamin b levels checked or a complete blood panel in a while those would be easy things to check, just in case.
I think you have to add motherhood into the equation as well. Even with the best children and with mothers who are in perfect health, keeping up with little ones and the work to care for them gives the sharpest women brain fog. Stress and discomfort on top certainly don't help the wiped out at the end of the day feeling many Moms of young children experience.
I hope your doctor has some good ideas on this. Hang in there Mom. Give yourself credit for ALL the things you do every day.