I guess the over sumplified stupid answer is “you just do” I havent yet and cant imagine what it will really be like, but when you lose people it seems impossible that you will move on from the way you feel at that time. But it is just a fact of life and something we all have to deal with at some point… Look after yourself and just try and enjoy the time you have.
My grandad is in a similar position, I`m going to visit him tomorrow as I never know when it will be my last chance at the moment…