I think your psychiatrist & psychologist are professionals, and as such you should rely on their judgement.

Rather than telling you what I think personally, I'm going to give you a few questions to consider:

Do you think it is normal to have "others" in your head? Is that something everybody experiences...

Don't you find it strange that the vast majority of people do not believe that demons exist. If they do exist, why can you detect them whilst other people can't?

Is it normal to think people are watching you, who are being controlled by some entity, "A"?

Why do you think your doctors, or the staff at the hospital would want to hurt you? Even if they are being controlled, is it not true they treat many other people for similar problems & yet no harm comes to them.

... just think about all that.

I'm sure you might have answers as to why only you experience these things or are being targeted... but remember, these are not normal things to think outwith mental illness. There are many other people who have thought similar things, only to get better on meds & realise they weren't true even though they seemed real at the time. It's very common for people who are psychotic not to think they are.

So, would it not stand to reason that you then also have the same problems, i.e. you do have psychosis?

Just some food for thought.