I'm a lot older than you are, but I feel your pain. When we first moved here from Houston, I never imagined it would be so hard to make friends/meet people here. But it was. I would invite people over to dinner and they would come and we would have a lovely evening, and then I would never hear from them again. Not even a thank-you note. One guest had the nerve to tell my husband a month or so later that I should throw another dinner party, because it was so nice. That one still floors me, as she never had responded with a thank-you, reciprocated with an invitation, or even invited us over for pizza and beer. I have no idea what is wrong with North Texas, but this is not a good place to make friends. I've perservered and found my niche and I have awesome friends, but it's been very hard. I do not know how people without children manage, as most of my friends now are friends I met through Kindermusik, dance class, preschool, playgroups, etc.
Keep on trying. There are lots of nice people out there. It'll just take a while.