The only thing that bothers me about being gay is that when I am old there will be no one to take care of me. I think this sounds like a poor reason to get a partner and adopt children but it passes through my mind.
I don't think you should worry about dying quite yet! May I recommend that you think about living? If you really get out there and live you will get to know a lot of children. You might wind up living in China or adopting a child. Life is full of surprises. Worrying about who will take care of you is the motivation of zillions of people. Please don't. Think more about who you are going to take care of. Get out there. Fall in love!