Cope Ahead?

I was curious on opinions and maybe some advice.

Ive been told that when you can cope ahead. But I don't fully get how. For example: My dog I've had forever gets sick sometimes and we think its the end... But almost always she gets better I know one day it will be her last but how do you truly try and prepare yourself for things.

I try but it seems like my brain wont let me it only hurts worse. Im not asking for only this situation but I wont talk about other stuff up here..

I dont really know what else to say so maybe someone could shine some light on this..

Stay safe, keep your head up...You have a purpose no matter what you think...

If anyone needs anything please feel free to text me im here.