Hey Sean,
It sounds like you are getting some IOIs, yes. Once might be chance, but sounds like it's a common thing.
For NLP, I recommend the old Bandler books: Using your brain for a change, frogs into princes, etc. You can also check out our NLP guy's stuff, he's very good and has some blog posts that are worth reading here:
http://www.puatraining.com/puablog/author/ben/
To get more comfortable speaking in groups, you've got to do some public speaking. I did a TEFL course (teaching English to foreigners) but there are hundreds of things that make you the centre of attention. Opening big groups of girls is good practice. If you stay around your social cirlce it's tough to become a new person, so you need to get out of it and push yourself. I've changed a lot in this regard, I was always the shy guy that never spoke, now I can do all the talking - if I want to. Although I usually just chill and let others speak, but at least it's an option now!
