How do I tell my girlfriend that she's no longer good enough for me?

Back when we got together, I settled for her, in spite of the fact that she's only just borderline attractive in my eyes, 6/10 at best, and completely lacking in sex appeal, because I was desperate and lacked self esteem, and felt that she was the best I could get with what I had to offer. But since then, I've gotten jacked up, I've gotten a promotion, I've gotten a new car and managed to purchase a house instead of renting a small apartment like I was doing back then. And now, there are dozens of women, at work and everywhere else I go, who've manifested interest in me, all of whom are miles hotter, sexier, nicer, kinder, cuter and more gentle than my girlfriend ever was- my girlfriend, who still makes out that I "should be eternally grateful" that she decided to be with me, who's been pressuring me to marry her ever since I got my promotion, and keeps telling me that "I'm the only girl who'll ever care about you, no-one else except me could ever love you". I deserve more, and I deserve better. How do I tell her?
How do I tell my girlfriend that she's no longer good enough for me?
8
4
Add Opinion