Real life will always get in the way and this can make it hard to cope. One strategy is to make sure that you make time for each other (and this applies if you are vanilla, BDSM or whatever). If that means booking hotel rooms, finding babysitters, fitting a lock to your bedroom door or whatever then do it. Try to have one day a week or month (whatever you can manage) where you shut out the real world and simply enjoy yourselves. Sometimes even just knowing that this day is planned will be a massive morale boost and even if sometimes things stop this day from happening or you have to have it very infrequently the thought of it will keep you going.