I'm just an observer of humankind (including myself) so my opinion isn't special, so ...
Your life with a major relationship stress and prolonged work stresses is mega stressful. So, I think you are a big survivor and you need to give yourself all kudos for that.
In stress, the attention does wander somewhat.
I think of thoughts like, 'they are discussing me in that meeting', as like watching a B movie or reading a pulp novel, somehow entertaining at the time, what helped me was to persuade myself that perhaps one percent or ten percent or 100 per cent of the meeting was concerned with normal business (!!!) by a process of probability or logical deduction i.e what they (the people in the meeting) are paid to do.
As for the 'poisoning' thoughts they are probably of the same kind. Only if you were to engage the authorities against the "would be poisoner" would that be paranoia.

It's a question of ownership.

If we describe our daft 'thoughts', others are going to think the worst of them, if they however are just wandering attention, there is no reason to describe them to others (except if that is going to give them a kind laugh not at our expense).

Ask the 'cinema projectionist in your head' not to show those daft reels!
In a typical day the 'projectionist' is checking with me several times a day and saying, 'was that sensible enough yet!!!'

Hoping that reassures you somewhat, but do listen to other opinions.

If an interviewer says you are too smart it means they feel threatened without good cause, they would just prefer a person like themselves.
I found I needed to learn a little more when smartness isn't relevant, but just blending into the scenery. And when to just walk away whatever people were saying.

Carry on surviving!
Best wishes.