I feel the same way. I am 40 and believe me it is a huge difference from even 35... In the past 5 years I have noticed many changes, not the least of which that my athletic endurance and strength have declined noticeably. It is also much much harder to keep weight off - MUCH harder.
I've always had good nutrition habits, and I honestly don't know what I could do without getting on drugs to make up for the loss...
I really don't want to be old, but I am sure attitudes change along with the body, even if they're lagging. My dad is 75 and still has a very active and full life, but just in different ways that he had in his younger years.
I hate the thought of being dependent upon others just as much as you, though, and honestly I can't understand why we don't accept allowing people to determine when they check out.
We could be having lavish parties and celebrating our lives with our loved ones and then take a nice, painless trip to the grave. Instead, we have to hide our emotional turmoil from those who love us, and ultimately go somewhere and take our own lives by monumental force, and put our loved ones through their own turmoil, and all because we have a big overbearing government that doesn't want to lose tax revenue.