Fear is part of our lives, even in relationships fear is constant, because we really don't want to lose the one we love. I've been married for 9 years and to this day I still have a lot of fears: betrayal, my wife leaving me, love breaking up, a lot of things, but the way is to try to live each day, each moment and make the most of every second you have with this person.
Worrying too much can end up getting in the way, so as well as a lot of patience, you have to be calm at certain times and let things happen in their own time, in their own flow.