Grades?

Hey guys, so I got a few B’s in HS (3 10-11th to be exact) and I wanted to explain the reason why I was unable to maintain my GPA. Usually, I am a 4.0 student but the beginning of my soph year, my father got ill (and is still ill) and so my mom had to take care of him, which thus forced me to take on many household duties in addition to caring for my younger brother. Do I put this on the additional comments section? And do you think the UC’s will be more lenient when looking at my GPA? If it helps I’ve taken a total of 18 honors/aps offered at my high school throughout my freshman-senior year and I am trying to maintain my grades, although it sometimes is hard because I have to juggle school work and taking care of the family.