Being uncomfortable talking to people can be a positive sign to people you're talking to – that you're less likely to waste their time, because you wouldn't do it for no reason at all. Of course, some people get conversations started with them all the time – attractive women, for instance – and so the dating sub-dynamic seems to have an accidental reverse correlation (there's a bad signalling dynamic where people think that a woman being more outgoing may suggest a lack of inbound interest – I think this is going away and feel obligated to point out that everyone likes kind people and signalling games that make people lonely are dumb).
Online dating makes the impulse to waste people's time worse. I'm no expert, though.
Just make sure to be interesting and kind – the danger of signalling your nervousness is that you're right to be nervous about a conversation, and in general it's good to take people's word on that sort of thing.