That's a hard one that I have beat myself up over for years also. I used to lay in bed and toss and turn thinking about being an old woman, completely alone because all of my loved ones had died before me. What's ironic is that my own death is my main fear. So, it's like I'm afraid to die and I'm afraid not to die. Crimeny! ;)
When I'm thinking these thoughts, I try to tell myself that at this moment, everything is ok and everyone is alive and that death is not an end but simply another realm of reality and that I will be with my loved ones again when it's all said and done (which is a whole other obsessive thought because who really knows what happens in the afterlife) (but I have to have faith for my own sanity).
Most importantly, I try to remember this thought: One day at a time. I know it's hard, but try to enjoy things as they are today and don't worry about what may come tomorrow.
