Sharing an event and some questions about PU

Hi,
I do not know if it's the right fourm to post this question but it felt the most suited.

First, I want to say that I don't deal with PU, and I just read some books (like The Game, the mystery method etc), I always wanted to get to this area but I keep postpone it endlessly. Today something happened and I felt a big urge to share and ask about it.

Let begin with the fact that I am shy, VERY.
My profession is programming (Surprise...) and today we were in conference were there was some cute girl and a guy trying to make people subscribe to magazines.
Me and my friend approached to their stand, and started to talk with them.
My friend talked with them for couple of seconds and then went, I stayed there and the girl suddenly said to me: "Here, maybe you choose some of our bla bla yada yada, and maybe for the coming valentine you could buy something for your GF".
After she said that I don't know what got into me and I said to myself that I have to just talk to her (I thought what the hell, let's do it!) and said: "If you are coming to a date with me I will sign"
SHE: "No problem", she than opened some form to sign in and asked me if I want to pay in credit card or some other type of payment.
I said: "Give me your number first, and after that will see where it goes"
She: "I will come with you, here my cell phone, when I give you my phone number you could even check and see it is real, and just you know that I eat a lot in a date."
The guy who works with her said: "you bet!" and she hit him the arm and smiled.
To keep long story short, in the end I sort of ran away and went embarrassed.
I just need to mention that during the phase with the credit card thing I didn't know what to do and I started to speak gibberish and shyness came upon me.

Now, it's clear to me that there was nothing of PU here (or at least some AFS behavior).
The fact that she said to me she will go out with me so easily shows that something here fishy - only some attempt to make me subscribe.
I didn't even want to go out with her, in spite of here good looks - maybe because of this I had the courage to talk to her, and I just said it's worth a shoot.

So, my problem is that after I left the conference, I felt so much sadness I don't know why - maybe because of this failure to do… what? I don't know (maybe because I didn't had a definite objective?
I know that many guys out there where excited about doing such a thing - talking to attractive girl in middle of a conference - but I "took it hard", Especially the part where she just wanted me to sign (maybe I felt used?)
The question is how you can overcome rejection?

And:
1) I am not sure at anything anymore, is that PU works? Does looks really doesn't matter? (Yes, I watched Sean Stephenson, but passed so much in life, that even he looks like one just trying to make money, and about the girls you can say it fake… not that I say it but I hope you understand my point).
2) The most important question: Do I have to choose between programming and girls? – As one of ID Software guys once said: “Either you stay up all night chasing that program you want to write, or you stay up all night chasing girls".
What to do? Is does two can be combined?