Whether it’s a relationship or a career, if the fear is driving you to make it last, then you are better off letting it go. To be able to enjoy anything, you need to be able to let go. If you want your marriage to thrive (not just last), I believe you have to be willing and able to let it go. Ultimately this is true with life in general; ironically, it is when we are able to let go of life (meaning, not afraid to die) that we finally become capable of enjoying it fully.