Well in this particular case where you developed 'feelings' or 'emotions' for this chick, perhaps it's not even that much about balls. I was in exactly same situation multiple times and looking at myself now, the first thing I would think about is me not getting hurt. So I would dream and fantasize until my battery runs dry and forget my obsession. I would never take the risk to gain something, because I was too afraid to be rejected, or thought of as a fool or being mucked. Now I feel sad when I remember how I invested myself and my thoughts for some stranger chick who never even knew me that much. Over and over.
It's all your brain messing you up - never does any good. But it's your current frame, you can't change it over night. Especially when there is one particular girl you are interested in and she gets all your attention. Then it was like I would become super weird (not in the way I act, but think).
A few phrases I would like to act by in future are -
Don't give a girl a special place in your mind if she had not deserved it.
Don't put anyone or anyones time above yours.
Be strategic, but don't over-analyze.
I'm far away from that 'dj mindset' to give any advanced recommendations, I'm on the very beginning of my road. But man it did feel good when I first acted by '3 sec rule' - it was raining and I saw this chick with umbrella, asked her to borrow me half of it. Had a pleasant talk, and gained an important experience. I decieded to act in a moment, my brain was 'wtf I'm I doing?!' but my mouth were faster. It's all natural, just control your brain and learn some finesses.