I feel the same way most of the time, however with GaymerX it hasn't been nearly as much of a problem for me. I went alone as a volunteer to the first one at the last minute even though I was nervous about it but I found everyone friendly and welcoming and totally willing to make new friends. The great thing about such a focused con is that pretty much everyone has something in common with you. If you are willing to say hi to someone new you should find it easy to meet new people. Just ask them what their favorite games are. I try to keep that spirit alive and I'm totally willing to meet and chat with anyone at the con
That said it is nice to have friends to fall back on as a sort of "safe space". I know there is a couple gay geeks facebook groups that often have quite a few people that attend and you may be able to find nearby people in them. Alternatively it is a great chance to meet up with long distance friends.