Questions concerning kids.

Hello =)I'm 16, live in Florida, and I'm gay. No one in my social life knows, nor do I plan to tell them. It's not that I don't embrace the fact that I like other guys, it's the fact that I don't personally want to date in high school, so I just don't bother telling anyone.The Internet's been extremely helpful in aiding me with some issues in the past, so I'll give this a shot. I only have two problems with being gay, and thinking about them gets me really anxious sometimes.I'm the last male in my family name, so it's my "responsibility" to carry it on. I personally don't see it as a huge deal, but it feels like the one thing I should be able to do and make my parents proud. (My parents, by the way, have said multiple times that they'd accept me no matter what my sexuality was.)I can't have biological kids with my husband. That one just makes me stupidly sad and upset. I'll be in college soon and I'll be taking very rigorous programs, meaning that I won't have a family until I'm well into my career. (And when I find the right person.) I just hate the idea of not having kids. If anyone here knows, how hard is adoption nowadays, and how will it be in ~20 years? I'm still going to love any child I can get, it's just hard to think that I can't show my mom HER grandkids one day.This got longer than I thought it would, so thank you for whoever read it and I hope I'll be able to grow out of some of these soon, or at least come to terms with it. Thanks =)