You have reverted (or grown) into your peak physical form. You will live until 100 years old, save for fatal physical trauma/accidents, but you will not age from your peak. How does this change your plans for life?
Basically you are now perfectly healthy, free of any disease, and will live to be 100. You’re not invulnerable or have any special powers that’ll keep you alive till 100, if you’re 49 and wrap your car around a tree, you ded. But now you don’t have to worry about health issues, aging, etc.