You should be crying, man.
How can you let a girl that follows you around get away?

Don't panic. Finding her is possible. I need more detail of where you were what was around; like...were there a lot of people, what did the area look like? Just give me an idea of the atmosphere. What you can do is go to the shops around there and describe her and ask if anyone has seen her. If you were in a hotel, ask about her there. If you were in a big area with a lot of people it's going to be harder. Explain to me also what do you mean "following me around" more detail needed on the situation.

And next time, when you see a girl you like. To strike a conversation you could ask her what time it is, although that is not best 'cause it ends quickly and once you have the time and still are not comfortable with talking to her, you'd probably just leave. Ask if she knows how to get somewhere. That way (and hopefully she knows how to get there) until she explains to you where to go, you'll already be comfortable enough with her to ask her other questions, like what her name is, or if she knows any good clubs around...you know stuff like that. Also, if she likes you, you won't have to do all the work - she will be talking and trying not to end the conversation to keep you there longer. But, I just can't believe that you would not take the chance provided it was so obvious she liked you and obviously you like her a lot.

Don't worry, if you really want to find her, you will.