You may want to attempt to improve your sleep. Foggy head with reduced cognition and memory loss are pretty major symptoms of long term inadequate sleep. They’re very common symptoms that parents of young children complain about, and can have some very long recovery times. Personally it took almost 6 months to recover once my first child started sleeping through the night. All it takes is an hour a night deficit for an extended period of time to really impact mental acuity, but you might not notice because it’s almost enough on a daily basis, and by the time the cumulative effects show up, it’s not always obvious sleep is the culpret.