I don't know if you have depression, or if there's some other reason you would see being 58 as "going back to the Earth"; but for the most part, people you age don't feel all that much like they're quite headed back to the Earth just yet. :)
If you have illness that's a different thing; but if you're healthy (or mostly healthy) I think you could use a new perspective on what being 58 can really be like. People who are fit often don't see a whole lot of "body aging". People who are out of shape can have "body aging" at any age. Sometimes, too, what people think is their body aging is really a medical condition that makes them feel tired or otherwise "older".
I think you need to keep exercising, take good care of yourself, make yourself look your own best, and stop thinking about the number, 58. After all, if you don't go back to the Earth until you're 99 you'll have spent a lot of time thinking about something you didn't have to. One thing, though, is that people who think a lot about dying often have clinical depression; so you may want to ask if there's a chance you have depression and consider seeking professional help for it.