>>74
She talks to you because she thinks of you as a friend from work. She probably thinks your an awkward but nice guy, which is why she tries to be friendly to you (judging from >>44). She wouldn't have conversations with you if she didnt want to talk to you, but its likely its just to fill time.
You're stuck in the friend zone, and i think trying to push for a relationship will alienate her and ruin your friendship. I advise you move on and look for someone else, and just stay friends with this girl. Dont waste time feeling bad over it (you said earlier you're good at getting over a girl, this is good), just move on and learn from your mistakes, especially STOP reading into her actions/things she says too much, it will just make you more insecure and depressed. Maybe ask her if shes got any cute single friends she can set you up with (if you dont like them, just date them so you can get experience/build confidence around girls). You might not want to, and instead want to wait for the right girl for you. Thats fine, but it wont hurt to get some experience while waiting for her right? You'll have a better chance of it working out that way. Maybe you'll have a chance with the current girl in the future, but right now i really dont think it will work out the way you want it to.
You need to be more relaxed, more confident, and less serious next time, both around the girl and away from her. DONT obsess over it, and pursue other hobbies. Go join a gym, or a martial arts class, or go play a sport, or join a book group, or anything you're interested in that will involve other people and social interaction. This will help build your confidence, which is your key problem. It will also force you to stop thinking about her all the time, as you'll have less time to do it.
And dont forget, we're all backing you. :]