Can't say enough praise about CBT for dealing with HA, it has helped tremendously with my issues. One of the things that really stuck with me is when my therapist asked me "OK, suppose you do have [insert life threatening disease au du jour], what changes now about how you live your life?" It not only reminds me to appreciate the days that I am healthy, but also that I will tackle any real issues head on and live life even more to the fullest if/when I do face a real threat. The other thing I do is no longer use google to find what might be wrong. The only place I allow myself to search symptoms is on here, and that just shows me how so many people have the same worries as me and are just as healthy. HA is so unfair in that it dominates our thoughts and takes us away from really being present with the ones we love.
And just to feed your reassurance addiction (we are all addicted to it here), I had massive twitches all over my body for a year with no real reason. My fingers, arms, tongue, calves, all twitched enough to easily be seen with the naked eye. That was 6 years ago and I am still here. Right now I am dealing with splinter haemorrhages under my nails and I bet I will be here in another 6 years. But either way, I won't let HA rob me of the time with my wonderful wife, family and friends. Stay strong and remind yourself to enjoy the present and not to dwell in the future, for that will always be uncertain.