Would chronic use of glycerin suppositories possibly cause brain fog?

Not likely: But why are you chronically using glycerin suppositories? "brain fog" alludes to feelings of confusion, poor concentration, and memory lapses. These symptoms could relate more to high blood pressure (listed on your clinical conditions) than they do to suppositories. In some people, propanolol can also cause a feeling of fuzzy thinking. You might want to discuss this with your own physician.

Gilbert's Disease?: This condition does list fatigue and difficulty in concentrating. Perhaps this is the cause as well as your hypertnesion. Chornic laxatives can cause headaches and possibly dehydration. Seems all these issues may be playing a role in your symptoms.