Your girlfriend isnt being selfish whatsoever! She is straightforward, and for that you really owe her enough respect and dignity to leave the relationship so she can find that person that can fulfill her expectations which by the way are perfectly normal in every way. If anything give her a big hug for being HONEST! Her honesty will save you years of anguish/grief/broken home....etc
P.S. Perhaps in the future you would bring your career goals up on the first date.
Have a nice day