Stress is an inevitable part of life. Used effectively, it can motivate us to accomplish more than we had imagined possible and jolt us toward reaching our potential.
If you have trouble staying focused regardless of the subjects and tasks, here are some tips:
(micro → macro, present → future)
Use your classes as an opportunity to identify tasks, jobs, and parts of the field you love or perhaps should avoid going forward. Some things are necessary hurdles to overcome but others are clues to what actually interests you vs. what makes your life miserable. If you have to FORCE yourself to do the work, and you hate it, and you procrastinate everything all the time, what do you think the next 20 or 30 years of your life will be like?