I don’t mean to pry, but your “dire circumstances” seem a little… dramatized? I’m not sure why missing a week of school in eighth grade would at all affect your high school transcript, or why your apparently severe illnesses only caused poor grades in some of your classes. My sincere apologies if these are more severe than I understand or than you are letting on, but it seems like you’re making excuses at this point quite frankly. If you include these circumstances in applications, I highly recommend asking your GC to do so so it doesn’t come off as such.
What concerns me is that the top/elite schools generally consider “extreme circumstances” to be cases of where the student demonstrated excellent grades, EC’s, promise, etc. before AND after a very traumatizing event. For example: a student with generally amazing grades who is an outstanding tennis player and quiz bowl captain has a particularly bad semester in sophomore year, receiving a string of C’s due to the death of a parent or a bout of a potentially life-threatening disease. This happens only in the one semester, and after that is generally back to the same level of achievement. In your case, there seems to be no period which you can point to and say “that was a result of my best effort!”- you have circumstances for everything, most of which are mild to moderate illnesses (many people get the flu or strep throat yearly and don’t suffer academically). How are colleges supposed to know what you are capable of if you’ve never been able to demonstrate it? I really am not trying to come off as mean, but I hope you understand what I’m getting at.