Struggling with Productivity and Mental Clarity

Foggy brain is horrible. It definitely can be overwhelming when you have to concentrate on learning and remembering something. In the past, when it came to studying, flash cards with key points seem to have helped me the most. I currently use a reminder app for tasks. A list or things put into calendar is not enough for me to remember about them. The reminder app gives options for date/time or place for notifications. I use a whiteboard in the kitchen (picture frame with white paper) to write down things as I think of them or use the last one. Also, post its for other reminders. If I have something specific I need to grab before I leave the house, I write it on a post it and stick it to the door.