For starters, you can apply for a job with the FBI here http://www.fbijobs.gov/03.asp
Also, the country were you went to school does not matter. There are only a few things that disqualify a person from working at the FBI, things like being a convicted felon. A full list is here https://www.fbijobs.gov/51.asp
Every position pays a different salary, but if you were hired there you would definitely be able to provide for your family
As far as your question about finding addresses, that would only be applicable if you were hired as special agent or in information technology. Given your medical training, those positions do not seem best suited to your needs. The FBI does not given access to all of its technologies to anyone who is an employee. Only those who need access to do their job have it.
My friend is an FBI forensic scientist