Let's tackle these one at a time. I'll address the time-line first.
Sept. 2000 - April 2001:
Complete third year of degree. By now, you should have taken all the courses
that will help you in the MCAT. These would include first year Physics, Inorganic
Chemistry, and English, second year Organic Chemistry, and probably Biochemistry
and some Biology courses.
August 2001:
Write the MCAT. Haha! Sucks to be you! :)
October 2001:
Receive MCAT scores from the AAMC. Prepare your applications, including all
reference letters, autobiographical essays, and a current transcript and send
them to the med schools. For Ontario schools (and I didn't apply to them,
so this is secondhand info), send application materials to OMSAS, who will
forward them to Ontario medical schools.
January-May 2002:
Sit tight and wait for interview/rejection letters. They could come at any
time in this interval. Make sure to do well in your fourth year studies. When
your fourth year marks are available (after April 2002 final exams), send
them to the medical schools that haven't rejected you.
May 2002-August 2002:
Harass the mailman on a daily basis looking for those rejection or acceptance
(!) letters from schools that you've interviewed at.
September 2002:
Start med school.
Now, the other question is one that I cannot answer with any certainty. Please take that into account when reading this. I know for a fact that OMSAS applications have a spot which you can mark if you feel your application is not representative of your true abilities. I would consider your personal hardships as directly affecting your schoolwork.
What you must do now, is prove that you can excell in your studies. An admissions committee right now, will see an applicant with a run of "bad luck" who has not proved (GPA wise) that they can thrive in a medical school academic environment. Therefore, my top recommendation now is to try to crush each of your remaining courses. If you can finish your degree with stellar marks, the admissions committee will now see a student whose marks dropped in times of great personal distress, but rebounded sharply upwards when their situation became more stable.
It is possible that a computer-generated GPA cutoff might torpedo your application before they read your autobiographical statement or your reference letters. In that case, those medical schools will be closed to you unless you pursue a graduate degree, but I believe there are many schools out there that would look at your extenuating circumstances, particularly if you finish your degree with very high marks.