The I.B. program offers great advantages for university admissions and career opportunities, but your mental and emotional health are crucial too. If the stress and sleep deprivation from the second language course are affecting your overall well-being, it might be worth reconsidering your path.
move closer with student who are good in that course more than you do for group study, also you can learn more about the course, check online for materials that can help you with that course. Good luck