Here are some ideas, and we hope others will add theirs:
-use colorful notes, pens, textflags
-plan carefully for deadlines, and break down studying into chunks
-plan time for sleep, health, foods, and time outside as much as you can
-switch topics - do a little of one subject, then do something else for a while
-make music playlists for focusing, relaxing, getting excited
-listen to nature sounds or calm.com when you're nervous or worried
Good luck! You can do it!