I don’t think you are listening to the advice posters are giving you.
One B+, one semester in high school will not be the reason you are accepted or rejected from colleges. If you like history, great take some additional history classes but do not do it in an attempt to “prove” you are an A student in history. It doesn’t matter, at all.
And to repeat, many, many kids go through divorce and death unfortunelty, do not use it as an excuse for “poor grades”.
Pursue your passions and do them with depth and meaning. Grades are just one of many factors in the admissions process. You are way overthinking this one B.
Good luck to you.