I have severe OCD, alongside a conglomerate of mental psychosis and illness. The only way past it is liken to suffocating. Hold your breath and refrain from inhaling as long as you can. The pressure and intensity that builds up is a lot like how OCD is. Holding your breath is how you're allowing OCD, and by building it up to get that breathe of air you're rewarding the system in place that made you suffer to begin with, rinse and repeat. By merely not holding your breath, or rather, by not committing your immediate attention to OCD and abstaining, reinforcing that it is a disorder and not true no matter how much it may hurt, you will be able to whittle your illness down to a more manageable level, perhaps to previous stability, if not lower. That also means it will be extremely painful cognitively and your immediate short term will suffer for it. I also suffer from audible and visual delusions, so I use the same method and just try to remind myself it is a mental error, not reality. I've thought about dimensional and esoteric what-ifs but ultimately I believe that these are mental delusions, and OCD is something that can be quelled so long as you make sure you can get it within grasps before it consumes you for decades. It is not to say you cannot come back from the brink, but I've self harmed intensely with knives to just get rid of the intrusions in the immediate - not something that is acceptable. OCD is heavily linked to the feeling of disgust, which leads to fear, I'm sure you can look into whatever areas of the brain control these states. Remember that it is a biological response and you will find peace.
