Men and women can’t be friends — I know it’s not a politically correct thing to say, but it’s true. And you’re seeing this from a front row seat! You made out with your “friend”, which is something friends don’t do, and you had an attempt at sex with her, but it sounds like things didn’t go well because she got dressed and left. Understand that friends don’t have sex with each other. That’s what lovers do, hookups do, partners and spouses do — but not friends. That said, if you have a “friend” who you’re attracted to, reconsider the relationship. Chances are it’s not a friendship — it’s something else. It could be a crush or a date or a date-to-be.
As for breaking your promise to her, that was bad. When you give someone your word, then get drunk and break it, you’ve lost their trust and embarrassed them by blurting out the secret you promised to keep. That’s a rough one to be able to get over, and if you can get her to forgive you, it will be with time.
My advice is to learn from these mistakes. Give her six months and then if you’re still feeling attracted to her, invite her on a date. Maybe she’ll have changed her mind by then. 😉 Time does heal all wounds.