I think it's worth asking what the fear is for, yourself right? Even if it is fear of not being there for your loved ones, it is for your loved ones. I don't mean to belittle the bond we have for our friends and family, but the point I want to make is that self can die before you die physically. As strange as it may sound, and as much aversion as we might have to the word death, it is basically being free from ourselves. What I've found though is it doesn't mean you are disconnected and don't care, but you are first free from yourself, and then you are free to be your 'self', you are just not limited to this identification you consider as self - you are much more than that.
An interesting fact is some who are convinced there is an afterlife are even more engaged in this one, because the attitude they have is there is only a limited amount of time here and we should contribute as much as we can while we are here. Regardless of what you think of the belief I think that's a great attitude, in contrast to the "I'm saved, so I won't bother with this life I'm just gonna wait for heaven." It's clear what the difference is isn't it? One is selfless, the other is selfish.