I think everything has that line between functional and non-functional, and paranoia isn't always psychosis... I read an article once that compared paranoia to phobias - there's a range and it's a problem if it severely impacts your functioning. I don't know how a layperson is supposed to make that decision for you though - have you talked to your pdoc?

I am paranoid that one day I will not be able to stop myself from blurting out something very inappropriate in the middle of a quiet scene like a university lecture or backstage while I'm doing theatre. I imagine myself doing all sorts of inappropriate things and I'm terrified that I'll actually do them, but I've been told that that paranoia is more akin to anxiety, phobias, or OCD than psychosis.