It's a bitch.
In some ways, its amazing - the layers of impossible completely unrelated phenomena together with totally implausible but just real enough to be viable connections even the world's best mad scientists couldn't dream up in a hundred years - if you could bottle it you'd put quantum supercomputers to shame.
But its horrific. It takes everything you know and experience and twists it in the most specific worst way possible to harm you and sow strife and doubt about what you know and what you've perceived and experienced. In ways and extents you never thought possible.
The slightest vague thought, slightly not heard utterance, even positive ones, leave wild open parks for paranoia to play in. Each opening spawns hundreds of new possibilities and open points to connect.
New information, about something completely different, even years later is then collated, and run against every single possible scenario your paranoia has ever come across, wondering not only does it confirm or deny that particular possibility at every event along the chain, but also, what new possibilities does it spawn off each and every data point that you hadnt previously considered. And then rerun with your data and recalculate new possibilities again. And then rerun and repeat again. And again.
You can even have voices in your head saying you things that you WISH were true, but know they're not, but the just possible enough viability of all the other bad things means you suffer the foolish hope that this outside impossibility might be stand even a small glimmer of hope.
Or two things that are mutually exclusive, such as times and places that are mutually exclusive that you still completely believe both situations happened and contribute to the same narrative.
You believe that things started with the best of intentions went wrong along the line and fit into a crippling warped narrative that leaves you questioning your reality
When you try to determine reality your paranoia again attacks that process - is the subject upset because you think that lowly or them, because of the emotional nature of the discussion, or because that's the reality they won't admit to, or because of a multiple layer bluff of these? So you model all four scenarios into your paranoid narrative and create 4 new possible timelines, that you then need to populate with paranoia-attached inference permutations of all the actual factual data points they subject provided.
The only way to combat paranoia is asking for objective factual observations of others involved. This is quite hard for others let alone to then piece together yourself. It so restrained.
Persons x and y were here.
They had phones out and on and I did/didn't see x on the screen.
It happened at y time.
I was with x and then said y (cross-reference with y's own statement)
Apply every single possible bias possibility from every known source, internal and external, and know context of persons/place/time/including theirs, your own, other people's and the difference in perspective.
Redraw narrative. Reapply entire process to apply new and missed possibilities and connections.