I can relate im just like you, im very anti-social and when it comes to talking i find it hard to express myself. For over a year now i've been talking to his guy were like best friends from the moment he introduced himself we clicked. He's my sole mate, i trust him and feel comfortable about telling/talking to him about anything.
You can always tell if some is interested in what your saying by the tone in their voice and the response. Do you both talk? or do you do most of the talking? if u do most of the talking you can always make him talk to make yourself more comfortable.
All this worrying is just paranoid because your not use to expressing yourself and you think into things to deep, once you get to know him better all the novelty should wear off
~*ºWhatever happens, happens for a reason.º*~