You made a huge step forward by figuring out what happened.
I think internet dating wouldn't be a bad idea for you. It's a really good exercise in finding out how to flirt, how to get to know a girl, how to not worry too much when someone doesn't reply to your messages,... I did it last year as a social experiment as well. Just like you, I was rather shy when it came down to meeting guys in a romantic way. I always tried to be a "buddy" and was very successful at being "just friends". Signing up at an online dating site forced me to try to be more than just friends with a guy. I went through a lot of awkward situations but I learned so much about body language, getting disappointed (frequently) and general social skills through it. And I gained a lot of confidence as well. In the end I did meet a guy with who I just connected straight away. Our first date lasted nine hours. Go figure. And he became my boyfriend. Awww...
Other ways to show you are interested in a person aside from asking questions are:
- touching them. When they say something funny, touch their upper arm for example, but don't over do it.
- eye contact, don't underestimate the power of eye contact.
- smile and laugh a lot, it's scientifically proven that smiling people are more attractive. Than again, it's just a nice thing to do. Be funny, use that sense of humor that you've got. Girls like a good sense of humor in a guy.
- listen to what the other person is telling, let them finish their story. You can show that you are listening by nodding or by just saying "yeah" every once in a while
- be original in your dates, take her to the zoo instead of yet another bar
It shows that you do want to make an effort for her.
You can find tons of these stuff online and in books. I hope it works out for you. I can only encourage you to do this and go for it whenever you feel the time it right.