Talked to an advisor, who reminded me that the tendency when taking on more work or difficult classes is to cut out activities outside of schoolwork: exercise, fun things/interests, and relaxation techniques. These are most important to keep up for stress relief and to engage the mind outside of schoolwork; typically are the first things to go, but are really needed for balance. Keeping up with providers too, especially if have a T or counselor, can be helpful as well and can be a priority. Productivity will actually decrease if not taking time away, so to definitely MAKE time for breaks by engaging in other activities and interests to recharge.
Things that knew but became so focused on studying that became short-sighted. Perhaps this reminder will help someone else as well.