I do not have an intamate knowledge of what the schools are looking for in an addendum, however, I would say try and stay more positive. It sounds like excuses, and not saying that its not reasonable, but they would rather hear of overcoming.
Phrase it someting like, "The grades that I recieved in the fall of 2002 are not a true indicator of my abilities or work ethic. I provided for my family in a tough period, which affected my academics, however, I was able to overcome this and ended very strongly".....just something along those lines. Pretend its an interview, always sping positive.