Regardless of wither a medical license is on the line you need to grow up and learn how to talk to a woman. If you are 20 something and not mature enough to handle a break up, how can you expect to be mature enough to handle the pressures of a M.D.?
I could not agree more. OP, lives could be in your hands someday. Try to learn from this.
Now on to OP's point.
Contrary to popular belief you don't just file a restraining order and then it's in effect. The wording and requirements vary from state to state, but basically she would have to file a petition for a domestic violence protection order (which is a pain in the butt). In this she will have to state exactly why she feels she needs protection from you. The reason generally has to involve some form of domestic violence or threat thereof, which would give her a reasonable fear of harm. If the claims indicate it a temporary protective order will be issued until the court date (if over turned this has no legal bearing). You will be served with the order and a summons. If you do not show up to the court date generally it will go into effect. Otherwise you show up, both tell your side of the story, and bring in any evidence. It is a civil matter, not criminal, meaning the burden of proof is lower. Instead of beyond a reasonable doubt she would only have to prove her claims were probable. Her claims would also have to meet certain standards set by the state for the order to be deemed necessary. If the ruling was in her favor, a protective order would be in place, barring you from any contact with her and also usually making it illegal for you to possess firearms while the order is in place (usually a few months, then it must be renewed, except in extreme cases).
This would be a civil action against you, not criminal, and is not the equivalent of being charged with domestic violence.
If the order is not granted there will be no ramifications for you. If it is granted, the effects on your career will largely depend on your states laws, as well as your school's policy. I doubt you would be barred from licensure, but
some schools have policies that reserve them the right to expel you for demonstrating poor character.
(I am not a lawyer, am not offering legal advice outside of my suggestion to learn to act like a mature adult, blah blah blah.)