Is it better to die young?

I know this will be quite the read and I apologize for that, but for those who hear me out and answer I thank you. Since I was a little boy, the idea of death frightened me. I know it seems a silly for a little boy to be so scared of something so far in distance, but it scared me none the less. Not to say that I am or was depressed. I'm always with friends and I do enjoy life and I have enough aspirations to fill a thousand lifetimes. But when I'm alone, I start to think... to wonder, is it all worth it? What is the point of living if you're only going to die? I realize that's an easily arguable one; however in cases such as this I believe most people will agree that sometimes logic doesn't seem to help. The other issue I face is the question of fleeting youth. Once again I realize that it's a stupid and possibly selfish thing to worry about at my age (I'm 21 if it helps). Is it better to die relatively young, and be remembered as the man you were, totally in control of your faculties. The downside obviously being that you don't live as long, but you live your whole life as a strong person who never needs to face the issue of being trapped in an old body. The idea of a catheter, a walker, and most frighteningly the slipping of my mind. I'm proud of my intelligence, I'm articulated and quick witted among other things. I've recently seen both my grandmothers slip into dementia; the idea of not knowing how to work a phone, thinking there are people sneaking into my place and rearranging my things when I sleep scares me more than anything else in the world. It's ironic, the two things in the world that I'm scared of, death and aging, are the two things I'll inevitably face. Somehow I'm not so reured that facing my fears will alleviate them. Anyway, after that little history of me I'll get to my real question. Is it better to say, smoke and die younger, or stay as healthy as you can and die older. The way I look at it, when I'm old and on my way out when I look back, will I have enjoyed all the fun I had with my friend during our smoke breaks (which for us are times to bond, talk about serious things and the like) or living a lot longer and using a walker and a colostomy bag. I'm leaning towards the former. I realize that there's no way to tell exactly how I'll be in however many years. In good shape or not, I'm just doing my best to live life well and hope that future me will look back and think I made the right choice. Thanks for reading, if you have any thoughts, answers, experience perhaps from a similar outlook. Once again, thank you for your time.