Thank you for sharing this difficult concern with us. You’ve said that you’ve wrestled with OCD (Obsessive Compulsive Disorder) since you were a child. It seems to me that since this diagnosis has already been made it would be a very good idea to follow up with treatment. The repetitive and intrusive imaginary discussions seem right at the core of an OCD style behavior.
A way to understand what is happening is that obsessive thoughts and behaviors can take many forms. Most of the compulsions are behaviors that can be observed, like washing hands or cleaning or arranging rituals. But some of the rituals may be mental. My best guess is that what you’ve explained sounds like a type of ritualized behavior. Keep in mind that I could be off on this because this isn’t a situation where I could diagnose someone — but the fact that you’ve been diagnosed with OCD and these patterns of thought follow a particular repetition and arrangement with your situation, makes me think having a discussion with a clinical psychologist or psychiatrist is the best thing.
For diagnosis and treatment the first thing is to make sure it is an OCD symptom and this can only be done with a trained professional. Typically, the type of therapy offered that is effective for OCD is cognitive-behavioral therapy, CBT. You can learn more about CBT here.