Frankly, I probably will after my parents die. It's weird because maybe a week ago my mother was talking to me about suicide, and I can't remember her exact words but it was like she was basically responding to my thoughts, essentially saying she wouldn't want me to do something like that just because she dies. But I don't really see what else to do. Being forever alone has consequences beyond the emotional. When my parents die, not only will I be alone but I'll be struggling financially. In the US, it's close to impossible to make it as a single person--you either need roommates, a spouse, a boyfriend or girlfriend you live with and split expenses with...it's just very hard to get by if you're all by yourself on one income, especially the kind of money employers are paying most people these days. I am also very close to my parents, especially my mother, and I can't imagine living without my mother.
Really, the fact that I'll never have a real relationship or any more real friends is actually a fairly distant third reason why I'd off myself, and I am not sure by itself it'd be enough of a reason to do it. I have lived life before struggling financially, and it was one of the unhappiest times of my life even with my parents still alive. Going to a job I hate all day that barely pays anything and living paycheck to paycheck (at best), then coming home to absolutely no one and having no one on earth who cares about me?...forget that. What's the point of living if you're always unhappy? (Not trying to encourage anyone by saying that, but...)