I see two confusing issues here. One is that the dollar will eventually lose its status as the world's reserve currency.
In order for that to happen, some other currency has got to take its place. It may be one currency, or it may be several swap deals (Japan and China, China and Aussie, etc).
At any rate, it won't likely happen inside of a decade. But when it does, the SECOND thing will happen, meaning the dollar will lose considerable value.
This, in and of itself, has two separate issues.
Issue one is that the fed's been printing money since its inception. The dollar has slowly been eroded by money printing inflation. This will continue.
The other issue is that once the dollar loses it's reserve status, the value of the dollar, its purchasing power, will drop significantly, since the majority of U.S. dollars are held in foreign banks. Everybody will be selling dollars, and they'll drop like the titanic.
How do protect yourself?
Understand a little bit about currency markets. Take a couple hours a week to stay abreast of international financial developments. Learn about hedge funds designed to protect against inflation. Learn to spot which foreign currencies are strong.
Whether you're paid in dollars or deer skins, you should be saving as much money as you can. Banks, or stock funds may not be the ticket anymore.
Don't blindly trust fund managers. Do your due diligence and find some decent investment vehicles that are mixes of hedge / growth.
And never, ever, listen to any investment advice from anybody on a forum.
Just suck it up and realize that, as a single man in today's world, understanding financial markets, how they operate, and how to identify appropriate investments is a requirement for financial survival.
Be willing to spend the time to do that, and you'll be fine.