I'm only posting so you don't make a rash decision based on the input of internet strangers. I assume your asking for help/perspective at SDN because you are interested in becoming a physician and are preparing for that long journey ahead of you.
First, relationships, especially romantic ones are special. Neither I, nor anyone here, has any idea of what kind of relationship you have with your boyfriend, so I'm skeptical (and appalled) by the clamoring to immediately and quickly break-up with your boyfriend because that relationship is inevitably some sort of hindrance for you reaching your career goals. Since we don't have that knowledge, you should caution yourself from blindly accepting the notion that "if I want success, I have to sacrifice a relationship I enjoy and cherish." Granted, the advice to break-up with your boyfriend might be valid for some (is the relationship new, tumultuous, riddled with drama etc.); in those cases, if you prioritize wanting a career in medicine over that type of relationship, it *would* be beneficial to make the cut, as it would be easier for yourself emotionally that having to do so later on.
Granted, I think the concern from the members here arose because he requested you move closer to him. Is it a demand, or a request? Is your relationship suffering because of distance or not? Can your situation change in the coming years/months were you might be able to visit each other more frequently?
I think you have a lot to consider, but appreciate what you have. Having developed a relationship over so many years, I am sure it is something very special, and I think it is a little foolish/naive to believe that one *has* to give that up in order to achieve dreams and goals. Both of you, working and communicating together, can make it work. You can stay with your boyfriend and become a doctor if you have a solid, mature relationship. That's the most important thing I wanted to communicate to you; so reflect more deeply before making any decision. If you want to talk more you can always PM me.