Explaining a drop in junior grade?

Hi, I am an international student studying at a us high school. I have A+ for the first two years of school, and a 5 on an AP course in sophomore year. But I got a B+ and most A-/A for my junior year, and I had a 3 for AP Cal BC and 4 for AP Chemistry. I went through a hard time in my junior year. I accidentally found out that my parents back in my hometown had secretly divorced and that my dad even had a daughter with the woman he has affair with. It was really hard to accept the reality, and acted like nothing happened, especially when living alone in another country. (I had to pretend that I didn’t know the divorce and the child thing due to complex reasons) I struggled to face my dad, who is a good father, but at the same time, an irresponsible, cruel husband. He is very strict to me, and we had very very serious fights this year, which affected my performance at school a lot. I don’t know if I should explain the situation in the additional information section. My common essays are all very positive, and I don’t want the admission officers to think I’m looking for excuse, but I worry that the grade drop will affect me. What should I do? Thank you.

I don’t think the B+ is significant enough to keep you out of college considering your past record, but if you have a guidance counselor it may be worth asking them explain that there have been many family struggles this year. The nitty gritty details are not as important and the admissions counselor does not need to know all of that.

Thank you