As a fellow scholar, I can understand how difficult juggling multiple subjects can be throughout a school year. I understand that there are so many confounding variables in life that we can not prepare for and hopefully you are willing to accept them, be they positive and negative, and learn to work and study through them when you can. You may struggle but remember how far you've gotten here by simply trying. Remember the milestones you've gotten over and stay in the present in order to appreciate the knowledge you've gained. Do NOT worry about being 100%, just worry whether or not you tried.