I'm finding my 50s are awesome and it's all about perspective. The one piece of advice I'd give is to realize life is a marathon not a race. Keep things in perspective. Things will happen and understand they aren't permanent. No matter what you go through, you got it. You can take care of it and it will always get better.
And one other thing. Stay in shape. Nothing is more important than your health. Always take time to care for yourself. Find something you love and it's fun.
Enjoy!