Although it is only by putting yourself in situations where you are not exactly comfortable that you get used to them, and they cease to be a problem for you. Maybe meeting a second person at your home would be good for you, if you can bring yourself to 'bite the bullet' and go through with it.
How not to feel uncomfortable ? Well no quick fixes for that, and as mentioned, it's down to having got used to it. But you can help by taking a deep breath before meeting them. Maybe realise they are thinking more about how they appear to you, than to worry so much about how you appear to them; so you need not be so self conscious. Maybe think of a few general things in advance that you can ask, for when you feel you need to contribute to the social chat ? Aside from that, just take it a moment at a time and except you aren't going to feel totally comfortable the first time you meet someone, at least not yet.