there are a couple of things that helped me, although I never really felt comfort from the idea, i guess 1 part doubt and 1 part I didn't believe I'd be good enough to make it through the big A.
You need to fully accept the idea its not going to happen, that this is all there is, we are conditioned to feel this is a morbid idea, but it really isn't. Once you break through and believe that, you get a feeling of peace with the idea. And you start living. You realize life is amazing, and your time is precious, the ones around you are special and you take everything for much more of what it is. It gives you so much more to "live" for.
Also you need to drop the idea of looking for comfort from an idea/answer... religion has conditioned us that there is 100% answer to everything and there just isn't. You need to get a zen like mentality that you are not in control, and you can't know all the answers so stop worrying and start living. Come to terms with this is it, and no one knows what happens when you die. Maybe you just cease to exist except in memories and legacy, or maybe you wake up from a dream in another reality, or maybe on a paradise earth, no one knows and we can't and wont know so just wait until you get there. It's hard to explain the enlightenment and peace you feel when you live this way, most witnesses will think it is trivial shallow existence because thats what we were taught, when its the contrary. You don't know what life is until you see its value this way.