Its seems to me that you've created what is known as a "trigger." A trigger is a specific activity that can be used to direct your energy and create a specific outcome. So, by you imagining a string, you are subconsciously directing your energy and your intent (which is what a spell does) to heal yourself as well as leading your friend to happiness. This is not a "power" or "extra special ability." It's just a subconscious (and sometimes conscious) connection to your magical abilities. It's kind of like a short-cut in magick, to put it simply.
If it's not a trigger, then you are just doing a marvelous job with visualization. If you can visualize the outcome, then you can sometimes manifest it too, as visualization can also direct your energy and intent.
At any rate, continue to use this method. It sounds like it's very successful at accomplishing what you desire. :)