Don't try to stop overthinking. When we fight the thought we want to stop, the brain constricts causing a shift back to the thinking to avoid the constriction. Stop trying. Stop not trying. This means just stop. When a thought about if you've really stopped well enough floats by, focus on a house you used to live in as a child or when younger. A senseless thought which has no interest for you is a good way to begin the silencing of your mind. Also understand that the compulsive thinking is on a subject or idea that you very likely cannot change right now. Probably can't change it at all because it's an illusion. Even if the thought is on death, it's not about death but it's on the word death that troubled you in the past and maybe has even recently. When we near the truth, the false self that sought problems or negativity or the uncontrollable cleverly sought the very idea or word that is controllable or else it wouldn't find it in hopes you'll either stop it or keep thinking you're the only one with it and it may never stop. Thoughts won't hurt you but how you used to perceive them will create the suffering. If you lost interest, let’s say, in death, what you'd lose interest in is time. BINGO. That is, in the scenario, really what the non problem you're disinterested in isn't. The ego likes worry because we've become accustomed to ironically feeling guilty for feeling happy. "Too good to be true. Won't last." That's the "little me.” Now comes indifference. As you're awakening into the present, the thought forms become much easier to SEE because that's really what you're doing by being. Another thing to consider is this example. When you have bought a new car, you're excited to have it and want to drive, obviously. Let's say you bought a new or newer Infiniti G 37 coupe wearing a pretty golden color. Notice within the next few days and within even this day as you drive around how many Infiniti vehicles you start seeing because you think they just weren't out there before. Can you imagine how many miracles and other invisible things that had been really visible that you didn’t see because you were looking for instead of seeing through. And you like seeing them because it validates that others also value the Infiniti as a fine automobile. Your awareness has both opened up and in an odd way narrowed and divided the playing field towards a very good thing for a fascinating reason. Intentionality and SEEING occurs when what is now important or of interest to you begins unconsciously at first seeing easily what you are wanting look at. I use this example because I have an Infiniti and like the make of car. Note that as human beings, we don't become very interested in something that we're not included in or able to relate to. When we are ALL included, there is increasing unity as when a tornado or the like hits our hometown. Something in common and it affects what we all have in common. Now, to the meat of this. Back to the overthinking of death as the example. Regardless of our religious beliefs or non beliefs or perhaps they aren't beliefs but personal experiences. Society and particularly religion tells us what to look at but not how to see more than the what but also the understanding and insight that will, paradoxically, cease the thinking about what we were told or conditioned to look at. Here's the key. Practice awareness. Be aware of occasions when you notice you are less aware when the intrusive thoughts float in. As you see that you are aware that you nodded off by habit, the habit must go because you've seen the habit and it can never lurk and lull you into that senseless but I understand: "I am thinking about death and I feel down and is there something wrong but I can't stop is seems so I must accept it and be glad when that thought leaves for a bit while I'm dist