I can so resonate with Sherlock Holmes! My mind is overactive just as Sherlock's, and would struggle just like he does without the support system I have built for myself and a purpose in life, which is my spiritual writing. Sherlock knows that without his crime-solving puzzles he would be bored out of his wits, and would sooner rather than later start his drug addiction again. But more than that, he needs purpose. That's why he continues to attend the addiction self-help group, and that's why he agreed to sponsor Kitty as a new defective just as he trained Dr. Watson before.
There was a beautiful scene in Elementary's Season Three when Sherlock was crying in his lonely apartment during a stay in London; he knew that he would start his addiction cycle again, but in the last minute Kitty knocked on his door and told him that she would be ready to start the training again. Sherlock gathered himself, told Kitty to come over the next day, and then threw the drugs into the fire. He found his purpose again, just as he had in the prior season by hooking up with Dr. Watson.
It is all about purpose. At the end of the day we all need "religion", that is, we need to hold onto someone we love and pursue something that gives us meaning. So it doesn't matter whether you have demons or not; neither does it matter whether you are on an uphill climb or whether you are gliding downhill. The only thing that matters is that you are surrounded by people you care for and that you see purpose in what you are doing. Finding purpose is elementary.