Well if sex is too much of a leap for you, you can start off by hugging her or kissing her when you feel the atmosphere. Physical contact counts.

I am not telling you to force a lady to sex.  But it is a better way to find out whether the lady is into you. If she pushes you away, apologize to her and move on. You are making progress if she stays put.

I read your story. You desperately wanting a date with her. She accepted it and called it off on the spot. I assumed you hang out with her quite often either with friends or just the two of you. You should have hug her and tell her how you feel when you were with you instead of playing the mind blowing waiting game.