It must be frustrating being set up by your aunt. I mean, it's sweet, but like you said you're not straight so having them introduce you to a girl and expect sparks to fly--must seem as though there's a lot of pressure put on you.
They may keep doing that if you don't tell them. Of course, you don't have to, that's your choice. It's just that, people have expectations and it can be hard when they don't know your preference. They'd be like "Do you have a girlfriend?" and everything and when you say no there's this awkward silence. I hate when that happens.
I think the GLBT group is a good idea (kinda like this site). That way you can discuss things with people you'd otherwise not talk about with others due to reasons you've already stated. Being part of a group of people who've gone through experiences similar to yours despite different backgrounds helps, I think.
As for health problems, perhaps you could make some lifestyle changes (workout, diet, etc.). I'm sorry if I sound all preach-y--God knows I myself consume more junk than anyone on this planet--but yeah, it would help to spend some time engaging in activities that could improve your health. Being happy in general can do that as well. And a boyfriend would be great, a boyfriend could make you happy, but you don't need one to be happy.
Of course, if you do come across a potential 'someone' then that can be wonderful. Like, someone who wants children as much as you do and basically looking for the same thing. I'm not saying you should date a carbon copy of yourself, just that, it'd be good to find someone who's walking down the same path as you.
Anyways, I wish you all the best and hope you find what you're looking for in life.