First, you must earn a bachelor's degree from a US university, completing all prerequisites for admission to medical school. You also need to take MCAT exams, and expect to need percentile score above the 95th percentile for the more competitive medical schools. Most med schools in US do not consider foreign applicants.
Expect to need a minimum of USD500,000 for 4 years of med school in US. You have a tremendous amount of hidden costs in med school. E.g. a friend spent over $2000 his first week in med school to get his medical bag & equipment, plus more for medical student coats, lab coats, etc. Intranet access for class review sessions, etc. - $135/month. There's NO way you are going to get away with a measly little $95,000/yr at Harvard. Expect your total costs will run at least $150,000/yr there. Probably more by the time you earn a bachelor's degree in US & can apply to med school.
As soon as you graduate, you return to your country of citizenship. There are no longer enough residency (post-MD degree clinical training positions) available for all the Americans earning MD degrees from US med schools & passing USMLE exams. You cannot expect any hospital to spend the vast time & money trying to get you a visa when they have an abundance of Americans available. You will have to return to your country, pass your country's medical exams, and find a residency position in your own country.