I think you should go for it.
I also think that today, right now, you should get a volunteer position in a hospital or clinic. Research in labs gets you no exposure to patients. As
LizzyM says, you need to smell them. You also need to see the administrativia, the politics, the conflicts, the frustrations, and how docs/nurses/staff deal with it all day after day. So start now and volunteer maybe 4 hours a week until you start med school. You have no credibility in "wanting to do medicine" without substantial exposure to the practice of medicine.
As for the rest of the process, look for the constantly-repeated advice here on SDN. Apply to *lots* of schools. Get started on your letters of recommendation early. Look for the advice from ScottishChap on coming from overseas. Look through the MCAT forum for strategies and myth-abatement.
Assume you're smart enough to do this. Also assume that you need coaching and inside info and that you need to be
teachable. In your shoes I'd be obsessive about three things:
1. find and follow every relevant discussion on SDN
2. get mentors who are practicing medicine who can reality check you
3. pay daily attention to health news, either in the NYT or the WSJ (preferably both)
Best of luck to you.